Nuclear Physics A最新文献

{"title":"Rotational stability of magnetic field in rotating quark-gluon plasma","authors":"Aritra Das,&nbsp;Kirill Tuchin","doi":"10.1016/j.nuclphysa.2025.123075","DOIUrl":"10.1016/j.nuclphysa.2025.123075","url":null,"abstract":"<div><div>Relaxation of the magnetic field in rigidly rotating quark-gluon plasma is studied. It is shown that the infrared modes satisfying <span><math><mi>k</mi><mo>&lt;</mo><mo>|</mo><mi>m</mi><mo>|</mo><mi>Ω</mi></math></span> and <span><math><mi>k</mi><mo>&lt;</mo><mo>|</mo><mi>m</mi><mo>±</mo><mn>1</mn><mo>|</mo><mi>Ω</mi></math></span>, where integer <em>m</em> is the projection of the orbital angular momentum along the rotating axis and Ω is the angular velocity, are unstable. The instability onset time and the magnetic field growth rate are computed for a standard initial profile of the magnetic field. Given the present phenomenological values of Ω and electrical conductivity <em>σ</em> the instability is not expected to be a significant factor in the field's time evolution.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1059 ","pages":"Article 123075"},"PeriodicalIF":1.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143759822","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":"Elastic scattering analysis of 10,11B+40Ca at 50 MeV using Woods-Saxon and folding potentials","authors":"Harun Al Rashid ,&nbsp;K. Kalita ,&nbsp;Amar Das ,&nbsp;Lakhyajit Sarma ,&nbsp;Nabendu K. Deb ,&nbsp;M. Bhuyan ,&nbsp;P. Sugathan ,&nbsp;Golda K.S. ,&nbsp;A. Jhingan ,&nbsp;N. Saneesh ,&nbsp;Mohit Kumar ,&nbsp;A. Parihari ,&nbsp;Honey Arora ,&nbsp;B.J. Roy ,&nbsp;J.J. Das","doi":"10.1016/j.nuclphysa.2025.123074","DOIUrl":"10.1016/j.nuclphysa.2025.123074","url":null,"abstract":"<div><div>An attempt has been made very recently to perform a scattering experiment on <span><math><mmultiscripts><mrow><mtext>B</mtext></mrow><mprescripts></mprescripts><none></none><mrow><mn>10</mn><mo>,</mo><mn>11</mn></mrow></mmultiscripts></math></span>+<span><math><mmultiscripts><mrow><mtext>Ca</mtext></mrow><mprescripts></mprescripts><none></none><mrow><mn>40</mn></mrow></mmultiscripts></math></span> systems at the energy of 50 MeV at General Purpose Scattering Chamber (GPSC) of Inter-University Accelerator Centre (IUAC), New Delhi, India. A comprehensive analysis of the elastic scattering data is carried out using different versions of optical potentials, such as the Woods-Saxon (WS) potential, the M3Y-Paris double-folding (DF) potential and the semi-microscopic Sao Paulo potential (SPP2). We have arrived at a new set of optical model (OM) parameters which are compared with the data obtained by Glover et al. (1980) at 46.6 MeV and 51.5 MeV. There is substantial change in the real and imaginary potential strengths when analyzed using WS potential. Both the systems exhibited absorption and showed structural differences between <span><math><mmultiscripts><mrow><mtext>B</mtext></mrow><mprescripts></mprescripts><none></none><mrow><mn>10</mn></mrow></mmultiscripts></math></span> and <span><math><mmultiscripts><mrow><mtext>B</mtext></mrow><mprescripts></mprescripts><none></none><mrow><mn>11</mn></mrow></mmultiscripts></math></span>, with the former having a deeper real potential and a more confined interaction region. With a combination M3Y-Paris (real) and WS Volume (imaginary) potential, experimental cross-sections are reproduced which also reveals the extended structure of <span><math><mmultiscripts><mrow><mtext>B</mtext></mrow><mprescripts></mprescripts><none></none><mrow><mn>11</mn></mrow></mmultiscripts></math></span>. SPP2 potential provides significant information on reaction dynamics providing larger proton and neutron radii of ¹¹B as compared to ¹⁰B. Finally, We extracted a new set of consistent OM parameters that is applicable in understanding the reaction dynamics of light-heavy ion interactions.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1059 ","pages":"Article 123074"},"PeriodicalIF":1.7,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738162","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":"Magnetic field at nucleus for ionized atoms","authors":"Andrzej Tucholski ,&nbsp;Zygmunt Patyk","doi":"10.1016/j.nuclphysa.2025.123073","DOIUrl":"10.1016/j.nuclphysa.2025.123073","url":null,"abstract":"<div><div>The determination of the magnetic field at the nucleus of ionized atoms was carried out and a linear dependence between the strength of the magnetic field at the nucleus and the nuclear effective charge divided by the principal quantum number was analyzed. The calculations of the magnetic field at the nucleus were done for a wide set of electron configurations within the framework of the relativistic Dirac-Hartree-Fock method. The results are compared to previously measured experimental <em>g</em>-factors.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1059 ","pages":"Article 123073"},"PeriodicalIF":1.7,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738161","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":"An improved unified fission model for α-decay half-lives","authors":"Fengzhu Xing ,&nbsp;Xiankai Le ,&nbsp;Nan Wang ,&nbsp;Yanzhao Wang","doi":"10.1016/j.nuclphysa.2025.123072","DOIUrl":"10.1016/j.nuclphysa.2025.123072","url":null,"abstract":"<div><div>An improved unified fission model (IMUFM) is developed for <em>α</em>-decay half-lives by introducing an analytical expression of the equivalent assault frequency and using a modified version of Woods-Sanox potential. The parameters of the analytical expression are determined by fitting the experimental <em>α</em>-decay half-lives from the ground state to ground state transitions. By comparing the agreement between the calculated ones and the experimental half-lives, it is found that the accuracy of IMUFM is improved significantly than its predecessor. Then the IMUFM is extended to study the <em>α</em>-decay properties of the superheavy nuclei with Z=118-120 isotopes. The <em>α</em>-decay half-lives of these nuclei are predicted within the IMUFM by inputting the <span><math><msub><mrow><mi>Q</mi></mrow><mrow><mi>α</mi></mrow></msub></math></span> values that extracted from the Weizsäcker-Skyrme-4 (WS4) model, the finite-range droplet model (FRDM) and the Koura-Tachibaba-Uno-Yamada (KTUY) formula, respectively. By observing the evolution of the <span><math><msub><mrow><mi>Q</mi></mrow><mrow><mi>α</mi></mrow></msub></math></span> values and the half-lives of Z=118-120 isotopes versus the neutron number N, the shell effects at N=178 and N=184 are shown evidently. At last, the dominant decay modes of <span><math><mmultiscripts><mrow><mn>118</mn></mrow><mprescripts></mprescripts><none></none><mrow><mn>296</mn></mrow></mmultiscripts></math></span>, <span><math><mmultiscripts><mrow><mn>119</mn></mrow><mprescripts></mprescripts><none></none><mrow><mn>297</mn></mrow></mmultiscripts></math></span> and <span><math><mmultiscripts><mrow><mn>120</mn></mrow><mprescripts></mprescripts><none></none><mrow><mn>298</mn></mrow></mmultiscripts></math></span> <em>α</em>-decay chains are investigated by studying the competition between <em>α</em>-decay and spontaneous fission (SF), which might be helpful for identifying these nuclides in future experiments.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1058 ","pages":"Article 123072"},"PeriodicalIF":1.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738732","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":"Insights from exotic hadrons through lattice QCD","authors":"Randy Lewis","doi":"10.1016/j.nuclphysa.2025.123070","DOIUrl":"10.1016/j.nuclphysa.2025.123070","url":null,"abstract":"<div><div>Nuclear physics is built on a solid understanding of individual nucleons, which can ultimately be described in terms of light quarks and gluons. The surprising recent discoveries of several tetraquark and pentaquark candidates, each containing both light and heavy quarks, offer new insight into the physics of quarks and gluons. Lattice QCD is a rigorous first-principles computational approach that can calculate some properties of these new exotic hadrons. The status of lattice QCD studies will be reviewed for a particular family of doubly heavy exotic hadrons, including possible implications for our understanding of light quark physics.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1058 ","pages":"Article 123070"},"PeriodicalIF":1.7,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687638","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":"Evaluation of fusion suppression factors for 6Li and 7Li using multilayer perceptron neural networks","authors":"D. Chattopadhyay","doi":"10.1016/j.nuclphysa.2025.123071","DOIUrl":"10.1016/j.nuclphysa.2025.123071","url":null,"abstract":"<div><div>Recent advancements have enhanced the measurement of complete fusion cross-sections, particularly for reactions involving weakly bound projectiles. It is well-established that the complete fusion cross-section for these nuclei is suppressed at above-barrier energies due to breakup effects. This study utilized feedforward Artificial Neural Networks (ANNs) with a Multilayer Perceptron architecture to estimate the complete fusion suppression factor for reactions involving ⁶Li and ⁷Li projectiles. By comparing ANN-predicted reduced fusion functions <span><math><mi>F</mi><mo>(</mo><mi>x</mi><mo>)</mo></math></span> with the Universal Fusion Function <span><math><msub><mrow><mi>F</mi></mrow><mrow><mn>0</mn></mrow></msub><mo>(</mo><mi>x</mi><mo>)</mo></math></span>, average suppression factors of 0.68 and 0.74 were determined for ⁶Li and ⁷Li, respectively. The Normalized Mean Squared Error (NMSE) for ⁶Li was 1.85% (training) and 1.92% (testing), while for ⁷Li it was 3.73% and 6.48%. Comparisons with Support Vector Regression, Random Forest Regression, and Gaussian Process Regression showed that ANNs provided superior accuracy, suggesting their viability for estimating fusion suppression factors. The study is further extended to <span><math><mmultiscripts><mrow><mi>Li</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>8</mn></mrow></mmultiscripts></math></span>, <span><math><mmultiscripts><mrow><mi>Be</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>7</mn></mrow></mmultiscripts></math></span>, <span><math><mmultiscripts><mrow><mi>Be</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>9</mn></mrow></mmultiscripts></math></span>, <span><math><mmultiscripts><mrow><mi>B</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>10</mn></mrow></mmultiscripts></math></span>, <span><math><mmultiscripts><mrow><mi>B</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>11</mn></mrow></mmultiscripts></math></span>, <span><math><mmultiscripts><mrow><mi>C</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>12</mn></mrow></mmultiscripts></math></span>, and <span><math><mmultiscripts><mrow><mi>C</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>13</mn></mrow></mmultiscripts></math></span> projectiles, revealing that fusion suppression is strongly influenced by the breakup threshold energy, with direct breakup dominating at sub-barrier energies.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1058 ","pages":"Article 123071"},"PeriodicalIF":1.7,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687637","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":"Absorption of ψ(2S) mesons in nuclei","authors":"E.Ya. Paryev","doi":"10.1016/j.nuclphysa.2025.123069","DOIUrl":"10.1016/j.nuclphysa.2025.123069","url":null,"abstract":"<div><div>In the present work we explore the inclusive <span><math><mi>ψ</mi><mo>(</mo><mn>2</mn><mi>S</mi><mo>)</mo></math></span> meson photoproduction from nuclei near the kinematic threshold within the collision model, based on the nuclear spectral function, for incoherent direct photon–nucleon charmonium creation processes. The model takes into account the final <span><math><mi>ψ</mi><mo>(</mo><mn>2</mn><mi>S</mi><mo>)</mo></math></span> absorption, target nucleon binding and Fermi motion. We calculate the absolute and relative excitation functions for production of <span><math><mi>ψ</mi><mo>(</mo><mn>2</mn><mi>S</mi><mo>)</mo></math></span> mesons on ¹²C and ¹⁸⁴ W target nuclei at near-threshold photon beam energies of 8.0–16.4 GeV, the absolute momentum differential cross sections for their production off these target nuclei at laboratory polar angles of 0^∘–10^∘, the momentum dependence of the ratio of these cross sections as well as the A-dependences of the ratios (transparency ratios) of the total cross sections for <span><math><mi>ψ</mi><mo>(</mo><mn>2</mn><mi>S</mi><mo>)</mo></math></span> production at photon energy of 13 GeV within the different scenarios for the <span><math><mi>ψ</mi><mo>(</mo><mn>2</mn><mi>S</mi><mo>)</mo><mi>N</mi></math></span> absorption cross section. We also calculate the A-dependence of the ratio of <span><math><mi>ψ</mi><mo>(</mo><mn>2</mn><mi>S</mi><mo>)</mo></math></span> and <span><math><mi>J</mi><mo>/</mo><mi>ψ</mi></math></span> photoproduction transparency ratios at photon energies around of 11.5 GeV within the adopted scenarios for this cross section. We demonstrate that both the absolute and relative observables considered reveal a definite sensitivity to these scenarios. Therefore, the measurement of such observables in future experiments at the upgraded up to 22 GeV CEBAF facility in the near-threshold energy region might shed light both on the <span><math><mi>ψ</mi><mo>(</mo><mn>2</mn><mi>S</mi><mo>)</mo><mi>N</mi></math></span> absorption cross section and on its part associated with the nondiagonal process <span><math><mi>ψ</mi><mo>(</mo><mn>2</mn><mi>S</mi><mo>)</mo><mo>+</mo><mi>N</mi><mo>→</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><mo>+</mo><mi>N</mi></math></span> at finite momenta, which are of crucial importance in understanding of charmonium production and suppression in high-energy nucleus–nucleus collisions in a search for the quark-gluon plasma.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1058 ","pages":"Article 123069"},"PeriodicalIF":1.7,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643769","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":"High-energy Coulomb scattering of spatially extended particles","authors":"M.L. Nekrasov","doi":"10.1016/j.nuclphysa.2025.123068","DOIUrl":"10.1016/j.nuclphysa.2025.123068","url":null,"abstract":"<div><div>We analyze pure Coulomb high-energy elastic scattering of charged particles (hadrons or nuclei), discarding their strong interactions. We distinguish three scattering modes, determined by the magnitude of the momentum transfer, in which particles behave as point-like, structureless extended, and structured composite objects. The results are compared in the potential and QFT approaches of the eikonal model. In the case of proton Coulomb scattering at the LHC the difference between these two approaches is significant. This indicates the unsuitability of the potential approach. However, in the case of Coulomb scattering of heavy nuclei, the leading one is the optical approximation, which formally reproduces the prescription of the potential approach.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1058 ","pages":"Article 123068"},"PeriodicalIF":1.7,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580167","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":"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}