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}
Pub Date : 2025-12-28DOI: 10.1016/j.nuclphysa.2025.123322
K. Prameela , S. Ramakrishna Reddy , Anjali Merin , K.V. Varsha , K.V. Jinu , Gonika , Alankar Singh , Rishabh Kumar , J. Gehlot , S. Nath , E. Prasad , A.M. Vinodkumar , P.V. Madhusudhana Rao , S. Appannababu
Fusion excitation function has been measured for the reaction 16O+138Ba around the Coulomb barrier energies using the recoil mass separator Heavy Ion Reaction Analyzer (HIRA). The fusion cross sections are strongly enhanced when compared to the predictions of the one dimensional barrier penetration model (1D-BPM) in the below barrier region. Fusion barrier distribution has been extracted from the experimental data to unveil the various channel couplings involved in the reaction. The measured fusion cross sections data and extracted barrier distribution have been analyzed with the coupled-channels (CC) calculations. These calculations indicate that the fusion excitation function has been reproduced quite well with the inclusion of one- and two-phonon vibrational states of the target nucleus. Whereas, one-phonon state alone was sufficient to reproduce the barrier distribution indicating that, coupling to the two-phonon state had no significant effect on the shape of the barrier distribution.
{"title":"Sub-barrier fusion dynamics in the reaction 16O+138Ba: Cross sections and barrier distribution studies","authors":"K. Prameela , S. Ramakrishna Reddy , Anjali Merin , K.V. Varsha , K.V. Jinu , Gonika , Alankar Singh , Rishabh Kumar , J. Gehlot , S. Nath , E. Prasad , A.M. Vinodkumar , P.V. Madhusudhana Rao , S. Appannababu","doi":"10.1016/j.nuclphysa.2025.123322","DOIUrl":"10.1016/j.nuclphysa.2025.123322","url":null,"abstract":"<div><div>Fusion excitation function has been measured for the reaction <sup>16</sup>O+<sup>138</sup>Ba around the Coulomb barrier energies using the recoil mass separator Heavy Ion Reaction Analyzer (HIRA). The fusion cross sections are strongly enhanced when compared to the predictions of the one dimensional barrier penetration model (1D-BPM) in the below barrier region. Fusion barrier distribution has been extracted from the experimental data to unveil the various channel couplings involved in the reaction. The measured fusion cross sections data and extracted barrier distribution have been analyzed with the coupled-channels (CC) calculations. These calculations indicate that the fusion excitation function has been reproduced quite well with the inclusion of one- and two-phonon vibrational states of the target nucleus. Whereas, one-phonon state alone was sufficient to reproduce the barrier distribution indicating that, coupling to the two-phonon state had no significant effect on the shape of the barrier distribution.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1067 ","pages":"Article 123322"},"PeriodicalIF":2.5,"publicationDate":"2025-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145924724","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 : 2025-12-28DOI: 10.1016/j.nuclphysa.2025.123321
Mamta Aggarwal , Pranali Parab , A. Jain , G. Saxena
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.
{"title":"Thermal evolution of shape coexistence in Mo and Ru isotopes","authors":"Mamta Aggarwal , Pranali Parab , A. Jain , 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":"2025-12-28","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}
Pub Date : 2025-12-25DOI: 10.1016/j.nuclphysa.2025.123320
Sakshi Shukla, Praveen C. Srivastava
In the present work, we study nuclear structure properties of the Pb isotopes within the framework of the nuclear shell-model. We have performed shell-model calculations using KHH7B and KHHE interactions. We have reported results for energy spectra, electromagnetic properties such as quadrupole moment (Q), magnetic moment (μ), B(E2), and B(M1) transition strengths, and compared the shell-model results with the available experimental data. The shell-model results for the half-lives and seniority quantum numbers (v) are also reported for the isomeric states.
{"title":"Nuclear structure properties of 184−194Pb isotopes and isomers","authors":"Sakshi Shukla, Praveen C. Srivastava","doi":"10.1016/j.nuclphysa.2025.123320","DOIUrl":"10.1016/j.nuclphysa.2025.123320","url":null,"abstract":"<div><div>In the present work, we study nuclear structure properties of the <span><math><msup><mrow></mrow><mrow><mn>184</mn><mo>−</mo><mn>194</mn></mrow></msup></math></span>Pb isotopes within the framework of the nuclear shell-model. We have performed shell-model calculations using KHH7B and KHHE interactions. We have reported results for energy spectra, electromagnetic properties such as quadrupole moment (<em>Q</em>), magnetic moment (<em>μ</em>), <em>B</em>(<em>E</em>2), and <em>B</em>(<em>M</em>1) transition strengths, and compared the shell-model results with the available experimental data. The shell-model results for the half-lives and seniority quantum numbers (<em>v</em>) are also reported for the isomeric states.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1067 ","pages":"Article 123320"},"PeriodicalIF":2.5,"publicationDate":"2025-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883368","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 : 2025-12-24DOI: 10.1016/j.nuclphysa.2025.123316
L.V. Ndala, M.L. Lekala
We demonstrate a significant impact of continuum-continuum couplings in the helium dimer on both elastic and breakup (dissociation) cross sections for the reaction , employing the Continuum Discretized Coupled Channels (CDCC) formalism with different model potentials, including Gaussian and exponential interactions. The resulting differential angular distributions elastic and breakup cross sections as well as elastic phase shifts are systematically analyzed and compared with available theoretical results in the literature. We find that the breakup cross section exhibits a threshold at zero energy, approaching zero as the center-of-mass energy tends to zero, while the elastic cross section approaches a finite constant value. The continuum-continuum couplings are shown to significantly modify the elastic phase shifts and to reduce their sensitivity to the specific form of the dimer potential. These findings highlight the essential role of continuum-continuum couplings in accurately describing low-energy three-body scattering and dissociation processes in weakly bound systems such as the helium dimer.
{"title":"The breakup dynamics of helium dimer","authors":"L.V. Ndala, M.L. Lekala","doi":"10.1016/j.nuclphysa.2025.123316","DOIUrl":"10.1016/j.nuclphysa.2025.123316","url":null,"abstract":"<div><div>We demonstrate a significant impact of continuum-continuum couplings in the helium dimer on both elastic and breakup (dissociation) cross sections for the reaction <span><math><mrow><msup><mrow></mrow><mn>4</mn></msup><msub><mrow><mrow><mi>H</mi></mrow><mi>e</mi></mrow><mn>2</mn></msub><mo>+</mo><msup><mrow></mrow><mn>4</mn></msup><mrow><mrow><mi>H</mi></mrow><mi>e</mi></mrow><mo>→</mo><msup><mrow></mrow><mn>4</mn></msup><mrow><mrow><mi>H</mi></mrow><mi>e</mi></mrow><mo>+</mo><msup><mrow></mrow><mn>4</mn></msup><mrow><mrow><mi>H</mi></mrow><mi>e</mi></mrow><mo>+</mo><msup><mrow></mrow><mn>4</mn></msup><mrow><mrow><mi>H</mi></mrow><mi>e</mi></mrow></mrow></math></span>, employing the Continuum Discretized Coupled Channels (CDCC) formalism with different model potentials, including Gaussian and exponential interactions. The resulting differential angular distributions elastic and breakup cross sections as well as elastic phase shifts are systematically analyzed and compared with available theoretical results in the literature. We find that the breakup cross section exhibits a threshold at zero energy, approaching zero as the center-of-mass energy tends to zero, while the elastic cross section approaches a finite constant value. The continuum-continuum couplings are shown to significantly modify the elastic phase shifts and to reduce their sensitivity to the specific form of the dimer potential. These findings highlight the essential role of continuum-continuum couplings in accurately describing low-energy three-body scattering and dissociation processes in weakly bound systems such as the helium dimer.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1067 ","pages":"Article 123316"},"PeriodicalIF":2.5,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883372","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 : 2025-12-24DOI: 10.1016/j.nuclphysa.2025.123317
L.V. Ndala , M.L. Lekala
The breakup dynamics of 6Li and 7Li projectiles on a 209Bi target have been investigated at various incident energies using the Continuum Discretized Coupled Channels (CDCC) method. Convergence of the angular distributions of the differential breakup cross sections is achieved with partial waves up to . The 6Li system shows strong angular dependence and pronounced effects of continuum-continuum couplings, especially at lower energies and backward angles, while the 7Li reaction exhibits weaker sensitivity to these couplings. The differences arise primarily from continuum and resonant structures and fragment-target interactions, rather than from the breakup thresholds.
{"title":"Dynamics of 6,7 Li breakups on heavy target mass","authors":"L.V. Ndala , M.L. Lekala","doi":"10.1016/j.nuclphysa.2025.123317","DOIUrl":"10.1016/j.nuclphysa.2025.123317","url":null,"abstract":"<div><div>The breakup dynamics of <sup>6</sup>Li and <sup>7</sup>Li projectiles on a <sup>209</sup>Bi target have been investigated at various incident energies using the Continuum Discretized Coupled Channels (CDCC) method. Convergence of the angular distributions of the differential breakup cross sections is achieved with partial waves up to <span><math><mrow><msub><mi>ℓ</mi><mrow><mi>max</mi></mrow></msub><mo>=</mo><mn>6</mn></mrow></math></span>. The <sup>6</sup>Li system shows strong angular dependence and pronounced effects of continuum-continuum couplings, especially at lower energies and backward angles, while the <sup>7</sup>Li reaction exhibits weaker sensitivity to these couplings. The differences arise primarily from continuum and resonant structures and fragment-target interactions, rather than from the breakup thresholds.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1067 ","pages":"Article 123317"},"PeriodicalIF":2.5,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883369","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 : 2025-12-24DOI: 10.1016/j.nuclphysa.2025.123319
A. Gokul, A.K. Rhine Kumar
The study of atomic nuclei exemplifies the challenge of solving many-body systems, where understanding nuclear structure unveils some of the universe’s deepest mysteries. Since the 1930s, molecular states and nucleon clustering in nuclei have been a topic of great interest. To explore these phenomena, we utilize the Relativistic Hartree-Bogoliubov (RHB) method, which naturally incorporates key relativistic effects such as scalar and vector potentials along with spin-orbit interactions. This research focuses on nucleon clustering in hot nuclei, employing the RHB framework at finite temperatures (FT-RHB). Key parameters, such as the density profile and nucleon-nucleon correlation function, play a crucial role in revealing the mechanisms of cluster formation and deeper aspects of nuclear structure at high temperatures.
{"title":"Clustering in hot 28Si","authors":"A. Gokul, A.K. Rhine Kumar","doi":"10.1016/j.nuclphysa.2025.123319","DOIUrl":"10.1016/j.nuclphysa.2025.123319","url":null,"abstract":"<div><div>The study of atomic nuclei exemplifies the challenge of solving many-body systems, where understanding nuclear structure unveils some of the universe’s deepest mysteries. Since the 1930s, molecular states and nucleon clustering in nuclei have been a topic of great interest. To explore these phenomena, we utilize the Relativistic Hartree-Bogoliubov (RHB) method, which naturally incorporates key relativistic effects such as scalar and vector potentials along with spin-orbit interactions. This research focuses on nucleon clustering in hot nuclei, employing the RHB framework at finite temperatures (FT-RHB). Key parameters, such as the density profile and nucleon-nucleon correlation function, play a crucial role in revealing the mechanisms of cluster formation and deeper aspects of nuclear structure at high temperatures.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1067 ","pages":"Article 123319"},"PeriodicalIF":2.5,"publicationDate":"2025-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883370","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 : 2025-12-22DOI: 10.1016/j.nuclphysa.2025.123313
Rayees Ahmad Yatoo , Sunil Kalkal , Akhil Jhingan
The dynamics of sub-barrier fusion reactions are well explained by incorporating channel coupling effects to various degrees of freedom, such as deformations and vibrations, within the coupled channel formalism. In many systems, sub-barrier fusion cross-sections are enhanced by couplings to inelastic excited states and nucleon transfer channels with positive Q-values. However, several systems show no such effect from positive Q-value transfer channels. Conventional coupled channel approaches effectively handle even-even systems, but for odd-even systems, odd-A nuclei are often approximated as pure rotors or vibrators, assuming ground state spin-parity and neglecting spin reorientation effects. Furthermore, single nucleon transfer is not included in codes like CCFULL, which only account for ground-state pair transfers without considering transfers involving excited states. To address these limitations, the quantum mechanical coupled reaction channel (CRC) code FRESCO is employed. For the 19F + 68Zn system, experimental data are explained by including couplings to inelastic states of both projectile and target. However, for 19F + 54,56Fe, 64Zn and 142,150Nd systems, inelastic couplings alone fail to reproduce fusion excitation functions (EFs). Couplings to one-proton (pickup) or triton (stripping) transfer channels with positive Q-values show no significant effect on sub-barrier fusion cross-sections. Overall, CRC calculations indicate that coupling to inelastic states of both projectile and target enhance sub-barrier fusion cross-sections. The treatment of the projectile/target nuclei based on certain assumptions has resulted in different sub-barrier fusion cross-sections in earlier studies. The current study suggests that channel coupling effects on fusion excitation function is a complex process in interaction with odd-A projectile and one needs to include exact spin-parity of odd-A nuclei in theoretical calculations.
{"title":"Disentangling channel coupling effects in interactions with 19F projectile using a coupled reaction channel approach","authors":"Rayees Ahmad Yatoo , Sunil Kalkal , Akhil Jhingan","doi":"10.1016/j.nuclphysa.2025.123313","DOIUrl":"10.1016/j.nuclphysa.2025.123313","url":null,"abstract":"<div><div>The dynamics of sub-barrier fusion reactions are well explained by incorporating channel coupling effects to various degrees of freedom, such as deformations and vibrations, within the coupled channel formalism. In many systems, sub-barrier fusion cross-sections are enhanced by couplings to inelastic excited states and nucleon transfer channels with positive Q-values. However, several systems show no such effect from positive Q-value transfer channels. Conventional coupled channel approaches effectively handle even-even systems, but for odd-even systems, odd-A nuclei are often approximated as pure rotors or vibrators, assuming ground state spin-parity and neglecting spin reorientation effects. Furthermore, single nucleon transfer is not included in codes like CCFULL, which only account for ground-state pair transfers without considering transfers involving excited states. To address these limitations, the quantum mechanical coupled reaction channel (CRC) code FRESCO is employed. For the <sup>19</sup>F + <sup>68</sup>Zn system, experimental data are explained by including couplings to inelastic states of both projectile and target. However, for <sup>19</sup>F + <sup>54,56</sup>Fe, <sup>64</sup>Zn and <sup>142,150</sup>Nd systems, inelastic couplings alone fail to reproduce fusion excitation functions (EFs). Couplings to one-proton (pickup) or triton (stripping) transfer channels with positive Q-values show no significant effect on sub-barrier fusion cross-sections. Overall, CRC calculations indicate that coupling to inelastic states of both projectile and target enhance sub-barrier fusion cross-sections. The treatment of the projectile/target nuclei based on certain assumptions has resulted in different sub-barrier fusion cross-sections in earlier studies. The current study suggests that channel coupling effects on fusion excitation function is a complex process in interaction with odd-A projectile and one needs to include exact spin-parity of odd-A nuclei in theoretical calculations.</div></div>","PeriodicalId":19246,"journal":{"name":"Nuclear Physics A","volume":"1067 ","pages":"Article 123313"},"PeriodicalIF":2.5,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145883367","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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