In this study, we examine how an isospin asymmetric nuclear medium affects the properties of pseudoscalar () and vector () mesons under different temperature values and degrees of isospin asymmetry, using the light-front quark model. To simulate the in-medium modifications of the constituent quark masses, we employ the chiral SU(3) quark mean field model. Our analysis focuses on evaluating the effective masses, weak decay constants, and distribution amplitudes (DAs) of B mesons in isospin-asymmetric nuclear matter. The calculated vacuum values of the B meson masses and decay constants show good agreement with existing experimental data, validating our approach to study the medium effects within the same framework.
{"title":"Impact of isospin asymmetric nuclear medium on pseudoscalar and vector B mesons","authors":"Tanisha, Satyajit Puhan, Navpreet Kaur, Harleen Dahiya, Arvind Kumar","doi":"10.1016/j.nuclphysa.2026.123330","DOIUrl":"10.1016/j.nuclphysa.2026.123330","url":null,"abstract":"<div><div>In this study, we examine how an isospin asymmetric nuclear medium affects the properties of pseudoscalar (<span><math><mrow><msup><mi>B</mi><mo>+</mo></msup><mo>,</mo><msup><mi>B</mi><mn>0</mn></msup></mrow></math></span>) and vector (<span><math><mrow><msup><mi>B</mi><mrow><mo>*</mo><mo>+</mo></mrow></msup><mo>,</mo><msup><mi>B</mi><mrow><mo>*</mo><mn>0</mn></mrow></msup></mrow></math></span>) mesons under different temperature values and degrees of isospin asymmetry, using the light-front quark model. To simulate the in-medium modifications of the constituent quark masses, we employ the chiral SU(3) quark mean field model. Our analysis focuses on evaluating the effective masses, weak decay constants, and distribution amplitudes (DAs) of <em>B</em> mesons in isospin-asymmetric nuclear matter. The calculated vacuum values of the <em>B</em> meson masses and decay constants show good agreement with existing experimental data, validating our approach to study the medium effects within the same framework.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1068 ","pages":"Article 123330"},"PeriodicalIF":2.5,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146036868","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}
Pub Date : 2026-01-16DOI: 10.1016/j.nuclphysa.2026.123331
E.Ya. Paryev
The possibility to study the nature of the famous charged bottomonium-like states Zb(10610) and Zb(10650), which is by far the best known, from their inclusive photoproduction off nuclei near the kinematic threshold is investigated within the collision model based on the nuclear spectral function. The model accounts for Zb(10610) ± and Zb(10650) ± production in direct photon–nucleon interactions as well as four different scenarios for their intrinsic configurations: compact tetraquarks, molecules of the two open-beauty mesons and two mixtures of both of them for each of Zb state. We calculate within these scenarios the absolute and relative excitation functions on 12C and 184W nuclei at photon energies of 61–90 GeV, the absolute momentum differential cross sections and ratios of them for their production off these target nuclei at laboratory polar angles of 0∘–5∘ and for photon energy of 75 GeV as well as the A-dependences of the transparency ratios for the Zb(10610) ± mesons at photon energy of 75 GeV. We show that the absolute and relative observables considered reveal distinct sensitivity to the Zb(10610) ± and Zb(10650) ± internal structures. Therefore, they might be useful for the determination of these structures from the comparison of them with the experimental data from the future high-precision experiments at the upcoming experimental facilities, such as the planned high-luminosity electron-ion colliders in the United States and China.
{"title":"Insights into the exotic charged states Zb(10610) and Zb(10650) from their photoproduction off nuclei","authors":"E.Ya. Paryev","doi":"10.1016/j.nuclphysa.2026.123331","DOIUrl":"10.1016/j.nuclphysa.2026.123331","url":null,"abstract":"<div><div>The possibility to study the nature of the famous charged bottomonium-like states <em>Z<sub>b</sub></em>(10610) and <em>Z<sub>b</sub></em>(10650), which is by far the best known, from their inclusive photoproduction off nuclei near the kinematic threshold is investigated within the collision model based on the nuclear spectral function. The model accounts for <em>Z<sub>b</sub></em>(10610)<sup> ± </sup> and <em>Z<sub>b</sub></em>(10650)<sup> ± </sup> production in direct photon–nucleon interactions as well as four different scenarios for their intrinsic configurations: compact tetraquarks, molecules of the two open-beauty mesons and two mixtures of both of them for each of <em>Z<sub>b</sub></em> state. We calculate within these scenarios the absolute and relative excitation functions on <sup>12</sup>C and <sup>184</sup>W nuclei at photon energies of 61–90 GeV, the absolute momentum differential cross sections and ratios of them for their production off these target nuclei at laboratory polar angles of 0<sup>∘</sup>–5<sup>∘</sup> and for photon energy of 75 GeV as well as the A-dependences of the transparency ratios for the <em>Z<sub>b</sub></em>(10610)<sup> ± </sup> mesons at photon energy of 75 GeV. We show that the absolute and relative observables considered reveal distinct sensitivity to the <em>Z<sub>b</sub></em>(10610)<sup> ± </sup> and <em>Z<sub>b</sub></em>(10650)<sup> ± </sup> internal structures. Therefore, they might be useful for the determination of these structures from the comparison of them with the experimental data from the future high-precision experiments at the upcoming experimental facilities, such as the planned high-luminosity electron-ion colliders in the United States and China.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1068 ","pages":"Article 123331"},"PeriodicalIF":2.5,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146036864","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}
Pub Date : 2026-01-15DOI: 10.1016/j.nuclphysa.2026.123333
Serdar Ünlü
A detailed quasi-particle random phase approximation (QRPA) analysis of two neutrino double electron capture transitions to the ground states and first excited states of 78Se and 130Xe is given in the present work. The experimental data related to the intermediate and final excited states have been reproduced using the adjustable strength parameters. The nuclear matrix elements and half-lives for two neutrino double electron capture have been calculated and compared with other calculations and corresponding experimental data. It can be said that the present approximation is usually successful in reproducing the experimental half-lives for two neutrino double electron capture.
{"title":"Two neutrino double electron capture of 78Kr and 130Ba in the QRPA framework","authors":"Serdar Ünlü","doi":"10.1016/j.nuclphysa.2026.123333","DOIUrl":"10.1016/j.nuclphysa.2026.123333","url":null,"abstract":"<div><div>A detailed quasi-particle random phase approximation (QRPA) analysis of two neutrino double electron capture transitions to the ground states and first excited states of <sup>78</sup>Se and <sup>130</sup>Xe is given in the present work. The experimental data related to the intermediate and final excited states have been reproduced using the adjustable strength parameters. The nuclear matrix elements and half-lives for two neutrino double electron capture have been calculated and compared with other calculations and corresponding experimental data. It can be said that the present approximation is usually successful in reproducing the experimental half-lives for two neutrino double electron capture.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1068 ","pages":"Article 123333"},"PeriodicalIF":2.5,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080543","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}
Pub Date : 2026-01-14DOI: 10.1016/j.nuclphysa.2026.123334
Evelyn Schuller , Horia Paşca
Understanding the potential energy landscape of fissioning nuclei is crucial for improving nuclear models and predicting fission fragment formation. In this study, we extract the potential energy in the mass coordinate from experimental mass distributions of Cf and Fm isotopes, assuming statistical equilibrium in the fissioning nucleus. By comparing the extracted potentials with those predicted by the statistical scission-point model, we investigate the validity of the equilibrium assumption and the accuracy of fission fragment formation at scission.
{"title":"Extraction of the potential energy in mass asymmetry coordinate from experimental mass distributions of f and m isotopes","authors":"Evelyn Schuller , Horia Paşca","doi":"10.1016/j.nuclphysa.2026.123334","DOIUrl":"10.1016/j.nuclphysa.2026.123334","url":null,"abstract":"<div><div>Understanding the potential energy landscape of fissioning nuclei is crucial for improving nuclear models and predicting fission fragment formation. In this study, we extract the potential energy in the mass coordinate from experimental mass distributions of Cf and Fm isotopes, assuming statistical equilibrium in the fissioning nucleus. By comparing the extracted potentials with those predicted by the statistical scission-point model, we investigate the validity of the equilibrium assumption and the accuracy of fission fragment formation at scission.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1068 ","pages":"Article 123334"},"PeriodicalIF":2.5,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146036867","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}
Pub Date : 2026-01-13DOI: 10.1016/j.nuclphysa.2026.123332
Larry Zamick
The previously considered (2j-1) rule for cross-conjugate pairs [44Sc, 52Mn] and [84Nb, 96Ag] is extended to a lighter pair [20F,24Na]. We also consider self-conjugate 8Li. It is noted and explained why the (2j-1) state in 20F is not isomeric.
{"title":"The (2j-1) rule for isomerism in odd-odd nuclei : Flip-flop behavior of cross-conjugates","authors":"Larry Zamick","doi":"10.1016/j.nuclphysa.2026.123332","DOIUrl":"10.1016/j.nuclphysa.2026.123332","url":null,"abstract":"<div><div>The previously considered (2j-1) rule for cross-conjugate pairs [<sup>44</sup>Sc, <sup>52</sup>Mn] and [<sup>84</sup>Nb, <sup>96</sup>Ag] is extended to a lighter pair [<sup>20</sup>F,<sup>24</sup>Na]. We also consider self-conjugate <sup>8</sup>Li. It is noted and explained why the (2j-1) state in <sup>20</sup>F is not isomeric.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1068 ","pages":"Article 123332"},"PeriodicalIF":2.5,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145993538","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}
Pub Date : 2026-01-13DOI: 10.1016/j.nuclphysa.2026.123327
S. Madhumitha Shree, M. Balasubramaniam
In this study, we introduce a machine learning approach to predict the logarithmic α-decay half-lives of ground-state emitters with a specific focus on extrapolating predictions to superheavy nuclei. The input data comprised of 344 experimentally determined α-decay half-lives. We utilized two complementary methodologies: XGBoost, an efficient ensemble learning algorithm, and PySR, a symbolic regression tool that generates interpretable empirical formulae. According to the SHAP (SHapley Additive exPlanations) explanation of the XGBoost model, features such as and were found to be very influential, which were chosen as input features for symbolic regression. PySR was trained to provide a simple empirical expression to calculate the logarithmic half-lives of α-decay. The derived expressions showed excellent agreement with the existing experimental data. Finally, we assess the extrapolation power of the models by predicting half-lives for the α-decay of various isotopes of superheavy nuclei of and . The results illustrate the power and physical accuracy of both approaches, making them suitable for guiding nuclear data evaluation in regions where experimental information is limited or unavailable.
{"title":"Machine learning and symbolic regression-based modeling of α-decay half-lives for superheavy nuclei","authors":"S. Madhumitha Shree, M. Balasubramaniam","doi":"10.1016/j.nuclphysa.2026.123327","DOIUrl":"10.1016/j.nuclphysa.2026.123327","url":null,"abstract":"<div><div>In this study, we introduce a machine learning approach to predict the logarithmic <em>α</em>-decay half-lives of ground-state emitters with a specific focus on extrapolating predictions to superheavy nuclei. The input data comprised of 344 experimentally determined <em>α</em>-decay half-lives. We utilized two complementary methodologies: XGBoost, an efficient ensemble learning algorithm, and PySR, a symbolic regression tool that generates interpretable empirical formulae. According to the SHAP (SHapley Additive exPlanations) explanation of the XGBoost model, features such as <span><math><msqrt><mi>Z</mi></msqrt></math></span> and <span><math><mrow><mn>1</mn><mo>/</mo><msqrt><mi>Q</mi></msqrt></mrow></math></span> were found to be very influential, which were chosen as input features for symbolic regression. PySR was trained to provide a simple empirical expression to calculate the logarithmic half-lives of <em>α</em>-decay. The derived expressions showed excellent agreement with the existing experimental data. Finally, we assess the extrapolation power of the models by predicting half-lives for the <em>α</em>-decay of various isotopes of superheavy nuclei of <span><math><mrow><mi>Z</mi><mo>=</mo><mn>107</mn></mrow></math></span> and <span><math><mrow><mi>Z</mi><mo>=</mo><mn>110</mn></mrow></math></span>. The results illustrate the power and physical accuracy of both approaches, making them suitable for guiding nuclear data evaluation in regions where experimental information is limited or unavailable.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1068 ","pages":"Article 123327"},"PeriodicalIF":2.5,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146036866","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}
Pub Date : 2026-01-12DOI: 10.1016/j.nuclphysa.2026.123329
Xuan Liu , Sheng Lin , Xun Chen
The strength of the interaction between heavy quarks is studied for heavy quarkonium () and doubly heavy baryons (QQq) at finite temperature and rapidity using the gauge/gravity duality in this paper. We show that this theoretical framework is capable of simultaneously and accurately describing both and QQq by fitting lattice potentials. In this framework, we study their interaction at long distances or low temperature and rapidity through effective string tension, while the interaction at short distances or high temperature and rapidity is studied through effective running coupling. Additionally, we plot their state diagram in the plane and systematically calculate their respective screening distances.
{"title":"The interaction of moving QQ¯ and QQq in the thermal plasma","authors":"Xuan Liu , Sheng Lin , Xun Chen","doi":"10.1016/j.nuclphysa.2026.123329","DOIUrl":"10.1016/j.nuclphysa.2026.123329","url":null,"abstract":"<div><div>The strength of the interaction between heavy quarks is studied for heavy quarkonium (<span><math><mrow><mi>Q</mi><mover><mi>Q</mi><mo>¯</mo></mover></mrow></math></span>) and doubly heavy baryons (QQq) at finite temperature and rapidity using the gauge/gravity duality in this paper. We show that this theoretical framework is capable of simultaneously and accurately describing both <span><math><mrow><mi>Q</mi><mover><mi>Q</mi><mo>¯</mo></mover></mrow></math></span> and QQq by fitting lattice potentials. In this framework, we study their interaction at long distances or low temperature and rapidity through effective string tension, while the interaction at short distances or high temperature and rapidity is studied through effective running coupling. Additionally, we plot their state diagram in the <span><math><mrow><mi>T</mi><mo>−</mo><mi>η</mi></mrow></math></span> plane and systematically calculate their respective screening distances.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1068 ","pages":"Article 123329"},"PeriodicalIF":2.5,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145993588","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}
Pub Date : 2026-01-11DOI: 10.1016/j.nuclphysa.2026.123323
N. Döpper, N. Kaiser
We present a calculation of neutrino-induced pion production off the nucleon up to one-loop order in covariant SU(2) chiral effective field theory with explicit inclusion of the Δ(1232) resonance. The calculation is carried out by employing the extended-on-mass-shell scheme to handle terms that violate power-counting, and the complex mass scheme to account for the complex pole position of intermediate deltas. Of the 25 next-to-leading and next-to-next-to-leading low-energy constants entering the amplitude, 17 are already determined in non-weak processes, while four are estimated by fitting the axial nucleon-to-delta transition form factors to the Adler parametrization. The remaining four low-energy constants are set to zero. Results for the total and differential cross sections are presented and compared to experimental data from ANL and BNL, and to results from models and event generators.
{"title":"Neutrino-induced single-pion production off the nucleon in covariant chiral perturbation theory with explicit delta degrees of freedom","authors":"N. Döpper, N. Kaiser","doi":"10.1016/j.nuclphysa.2026.123323","DOIUrl":"10.1016/j.nuclphysa.2026.123323","url":null,"abstract":"<div><div>We present a calculation of neutrino-induced pion production off the nucleon up to one-loop order in covariant SU(2) chiral effective field theory with explicit inclusion of the Δ(1232) resonance. The calculation is carried out by employing the extended-on-mass-shell scheme to handle terms that violate power-counting, and the complex mass scheme to account for the complex pole position of intermediate deltas. Of the 25 next-to-leading and next-to-next-to-leading low-energy constants entering the amplitude, 17 are already determined in non-weak processes, while four are estimated by fitting the axial nucleon-to-delta transition form factors to the Adler parametrization. The remaining four low-energy constants are set to zero. Results for the total and differential cross sections are presented and compared to experimental data from ANL and BNL, and to results from models and event generators.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1067 ","pages":"Article 123323"},"PeriodicalIF":2.5,"publicationDate":"2026-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145977049","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}
Pub Date : 2026-01-10DOI: 10.1016/j.nuclphysa.2026.123328
Mohammed Hassen Eid Abu-Seileek, Saed J. Al Atawneh
We present a systematic investigation of the thermal properties of the doubly magic nucleus 56Ni under thermal excitation, employing the Finite-Temperature Hartree-Fock (FTHF) method with two distinct realistic nucleon-nucleon (NN) interactions: the Reid Soft Core (RSC) and Nijmegen (Nijm.II) potentials. The primary objective is to quantify the sensitivity of key thermodynamic observables -including binding energy, root-mean-square radius, entropy, Helmholtz free energy, and the single-particle spectrum - to the choice of the underlying nuclear force. Calculations were performed in a no-core model space of six major oscillator shells across a temperature range of 0 to 8 MeV. Our results reveal that while macroscopic thermal trends are robust and largely potential-independent, critical quantitative differences emerge. The RSC potential predicts a higher excitation energy (205 MeV) for a 44.5 % volume expansion at MeV compared to 189 MeV for Nijm.II. Furthermore, we identify distinct interaction-dependent thresholds, such as a crossover in nuclear radius at MeV and a divergence in energy at MeV. Our comparative analysis with previous 40Ca calculations reveals that the thermal response of 56Ni is markedly different despite both being doubly magic. While 40Ca exhibits a volume expansion of 13.4 % at T = 8 MeV, 56Ni expands by only 3.5 %, scoring its stronger resistance to thermal swelling. Similarly, the entropy increase is substantially lower in 56Ni, with a slope reduction of nearly 40 % relative to 40Ca. Moreover, the crossover temperature at which RSC and Nijm.II potentials diverge occurs at T ≈ 2.4 MeV in both nuclei, but the subsequent divergence is quantitatively smaller in 56Ni, reflecting its larger shell gap and binding energy. These results establish that the thermal response is strongly mass-dependent, with heavier doubly magic nuclei displaying enhanced thermodynamic stability.
{"title":"Thermal properties of the doubly magic 56Ni nucleus","authors":"Mohammed Hassen Eid Abu-Seileek, Saed J. Al Atawneh","doi":"10.1016/j.nuclphysa.2026.123328","DOIUrl":"10.1016/j.nuclphysa.2026.123328","url":null,"abstract":"<div><div>We present a systematic investigation of the thermal properties of the doubly magic nucleus <sup>56</sup>Ni under thermal excitation, employing the Finite-Temperature Hartree-Fock (FTHF) method with two distinct realistic nucleon-nucleon (NN) interactions: the Reid Soft Core (RSC) and Nijmegen (Nijm.II) potentials. The primary objective is to quantify the sensitivity of key thermodynamic observables -including binding energy, root-mean-square radius, entropy, Helmholtz free energy, and the single-particle spectrum - to the choice of the underlying nuclear force. Calculations were performed in a no-core model space of six major oscillator shells across a temperature range of 0 to 8 MeV. Our results reveal that while macroscopic thermal trends are robust and largely potential-independent, critical quantitative differences emerge. The RSC potential predicts a higher excitation energy (205 MeV) for a 44.5 % volume expansion at <span><math><mrow><mi>T</mi><mo>=</mo><mn>8</mn></mrow></math></span> MeV compared to 189 MeV for Nijm.II. Furthermore, we identify distinct interaction-dependent thresholds, such as a crossover in nuclear radius at <span><math><mrow><mi>T</mi><mspace></mspace><mo>≈</mo><mspace></mspace><mn>5.6</mn></mrow></math></span> MeV and a divergence in energy at <span><math><mrow><mi>T</mi><mspace></mspace><mo>≈</mo><mspace></mspace><mn>2.4</mn></mrow></math></span> MeV. Our comparative analysis with previous <sup>40</sup>Ca calculations reveals that the thermal response of <sup>56</sup>Ni is markedly different despite both being doubly magic. While <sup>40</sup>Ca exhibits a volume expansion of 13.4 % at <em>T</em> = 8 MeV, <sup>56</sup>Ni expands by only 3.5 %, scoring its stronger resistance to thermal swelling. Similarly, the entropy increase is substantially lower in <sup>56</sup>Ni, with a slope reduction of nearly 40 % relative to <sup>40</sup>Ca. Moreover, the crossover temperature at which RSC and Nijm.II potentials diverge occurs at <em>T</em> ≈ 2.4 MeV in both nuclei, but the subsequent divergence is quantitatively smaller in <sup>56</sup>Ni, reflecting its larger shell gap and binding energy. These results establish that the thermal response is strongly mass-dependent, with heavier doubly magic nuclei displaying enhanced thermodynamic stability.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1067 ","pages":"Article 123328"},"PeriodicalIF":2.5,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145977050","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}
Pub Date : 2026-01-10DOI: 10.1016/j.nuclphysa.2026.123326
Mohd Faizan Khan , Avinash Agarwal , I.A. Rizvi , Anuj Kumar Jashwal , Harsh Vardhan , Munish Kumar , S. Ali , M. Gull , Satyam Gangwar , Kamal Kumar , S. Dutt , A.K. Chaubey
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 16O +89Y systems at energies ≈ 4 - 7 MeV / nucleon. A standard stacked foil activation technique followed by offline γ-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, xn, pxn, αxn and 2αxn channels are investigated. Whereas, the measured excitation function of ERs populated via some xn (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 α 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 (μA), Coulomb factor (ZPZT) and the variation in neutron excess in the target nucleus (N-Z) play a significant role in the onset of incomplete fusion.
{"title":"Measurement and analysis of excitation function for 16O+89Y at energies 4–7 MeV/nucleon","authors":"Mohd Faizan Khan , Avinash Agarwal , I.A. Rizvi , Anuj Kumar Jashwal , Harsh Vardhan , Munish Kumar , S. Ali , M. Gull , Satyam Gangwar , Kamal Kumar , S. Dutt , 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 <sup>16</sup><em>O</em> +<sup>89</sup><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<sub>A</sub></em>), Coulomb factor (<em>Z<sub>P</sub>Z<sub>T</sub></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":"2026-01-10","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}
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