The European Physical Journal A最新文献

{"title":"The (^{12})C((alpha ,gamma )^{16})O reaction, in the laboratory and in the stars","authors":"R. J. de Boer,&nbsp;A. Best,&nbsp;C. R. Brune,&nbsp;A. Chieffi,&nbsp;C. Hebborn,&nbsp;G. Imbriani,&nbsp;W. P. Liu,&nbsp;Y. P. Shen,&nbsp;F. X. Timmes,&nbsp;M. Wiescher","doi":"10.1140/epja/s10050-025-01537-1","DOIUrl":"10.1140/epja/s10050-025-01537-1","url":null,"abstract":"<div><p>The evolutionary path of massive stars begins at helium burning. Energy production for this phase of stellar evolution is dominated by the reaction path 3<span>(alpha rightarrow ^{12})</span> C<span>((alpha ,gamma )^{16})</span>O and also determines the ratio of <span>(^{12})</span>C/<span>(^{16})</span>O in the stellar core. This ratio then sets the evolutionary trajectory as the star evolves towards a white dwarf, neutron star or black hole. Although the reaction rate of the 3<span>(alpha )</span> process is relatively well known, since it proceeds mainly through a single narrow resonance in <span>(^{12})</span>C, that of the <span>(^{12})</span>C<span>((alpha ,gamma )^{16})</span>O reaction remains uncertain since it is the result of a more difficult to pin down, slowly-varying, portion of the cross section over a strong interference region between the high-energy tails of subthreshold resonances, the low-energy tails of higher-energy broad resonances and direct capture. Experimental measurements of this cross section require herculean efforts, since even at higher energies the cross section remains small and large background sources are often present that require the use of very sensitive experimental methods. Since the <span>(^{12})</span>C<span>((alpha ,gamma )^{16})</span>O reaction has such a strong influence on many different stellar objects, it is also interesting to try to back calculate the required rate needed to match astrophysical observations. This has become increasingly tempting, as the accuracy and precision of observational data has been steadily improving. Yet, the pitfall to this approach lies in the intermediary steps of modeling, where other uncertainties needed to model a star’s internal behavior remain highly uncertain.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 4","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epja/s10050-025-01537-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The soft dipole resonances and E1 responses of 6He and 6Be","authors":"Y. H. Yang,&nbsp;Y. G. Ma,&nbsp;Z. C. Xu,&nbsp;S. M. Wang","doi":"10.1140/epja/s10050-025-01543-3","DOIUrl":"10.1140/epja/s10050-025-01543-3","url":null,"abstract":"<div><p>⁶He, known as a Borromean nucleus with a 2<i>n</i>-halo structure, and its mirror partner ⁶Be, the lightest 2<i>p</i> emitter, provide an excellent framework for exploring soft dipole resonance and nuclear structure. Despite previous studies on these nuclei, the potential presence of soft dipole resonance (<span>(J^pi = 1^-)</span>) had rarely been predicted before. In this work, we will investigate the presence of <span>(1^-)</span> resonance states in the complex energy plane, focusing on how the soft dipole resonance impacts the <i>E</i>1 transitions/response. Using the Gamow coupled-channel method for three-body calculations, we analyze the structures and soft dipole resonance of ⁶He and ⁶Be mirror systems, further exploring the <i>E</i>1 transition strengths of ⁶He through Green’s function method. The results show that the structural properties of ⁶He and ⁶Be show similar behavior. Notably, there are significant di-nucleon correlations in the <span>(0^+)</span> ground-state of both nuclei. Additionally, we observed a significant enhancement in <i>E</i>1 transition strengths at the energy corresponding to the <span>(1^-)</span> state. This indicates the presence of relative motion between the valence nucleons and the core.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 4","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143740692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"From reactors to stars","authors":"Maurizio Busso,&nbsp;Maria Lugaro,&nbsp;Alberto Mengoni,&nbsp;René Reifarth,&nbsp;Michael Wiescher","doi":"10.1140/epja/s10050-025-01542-4","DOIUrl":"10.1140/epja/s10050-025-01542-4","url":null,"abstract":"<div><p>This <i>Eur. Phys. J. A</i> volume <b>58</b> is dedicated to the life and work of Dr. Franz Käppeler from Karlsruhe Institute for Technology (KIT) who died on 20 November 2021, after a short illness. He was one of the leading experimentalists in the field of experimental nuclear astrophysics in Germany and worldwide for decades. Many of the authors of this volume knew Franz personally and many others were directly or indirectly inspired by his work and personality. All references in this introductory article refer to publications in this volume, not necessary to actual work by Dr. Käppeler.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 4","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epja/s10050-025-01542-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143740844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis of actinides and short-lived radionuclides during i-process nucleosynthesis in AGB stars","authors":"Arthur Choplin,&nbsp;Stephane Goriely,&nbsp;Lionel Siess,&nbsp;Sébastien Martinet","doi":"10.1140/epja/s10050-025-01522-8","DOIUrl":"10.1140/epja/s10050-025-01522-8","url":null,"abstract":"<div><p>A complex interplay between mixing and nucleosynthesis is at work in asymptotic giant branch (AGB) stars. In addition to the slow neutron capture process (s-process), the intermediate neutron capture process (i-process) can develop during proton ingestion events (PIEs). In this paper, after quickly reviewing the different modes of production of heavy elements in AGB stars that have been identified so far, we investigate the synthesis of actinides and other short-lived radioactive nuclei (SLRs, <span>(^{60})</span>Fe, <span>(^{107})</span>Pd, <span>(^{126})</span>Sn, <span>(^{129})</span>I, <span>(^{135})</span>Cs, and <span>(^{182})</span>Hf) during i-process nucleosynthesis. AGB stellar models with initial masses <span>(1 le M_textrm{ini}/M_{odot }le 3)</span>, metallicities <span>(-3 le )</span> [Fe/H] <span>( le 0)</span>, and different overshoot strengths were computed with the stellar evolution code <span>STAREVOL</span>. During PIEs, a nuclear network of 1160 isotopes is used and coupled to the transport equations. We found that AGB models with [Fe/H] <span>(&lt;-2)</span> can synthesize actinides with abundances sometimes greater than solar values. The <span>(^{60})</span>Fe yield scales with the initial metallicity, while the <span>(^{107})</span>Pd, <span>(^{126})</span>Sn, <span>(^{129})</span>I, <span>(^{135})</span>Cs, and <span>(^{182})</span>Hf yields follow a similar pattern as a function of metallicity, with a production peak at [Fe/H] <span>(simeq -1.3)</span>. At [Fe/H] <span>(&lt;-1)</span>, the fraction of odd Ba isotopes <span>(f_textrm{Ba,odd})</span> is predicted to vary between 0.6 and 0.8 depending on the initial mass and metallicity. Nuclear uncertainties on our 1<span>(~M_{odot })</span>  [Fe/H] <span>(=-2.5)</span> model lead to <span>(f_textrm{Ba,odd})</span> ranging between 0.27 and 0.76, which is clearly above the s-process value. AGB stars experiencing PIEs appear to be potential producers of actinides and SLRs, particularly at low metallicity (except for <span>(^{60})</span>Fe). Galactic chemical evolution modelling is required to assess their possible contribution to the galactic enrichment.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 4","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143740843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Decays (tau rightarrow f_0(pi ,K) nu _tau ) and (tau rightarrow 3 pi nu _tau ) accounting for the contribution of (f_0(500))","authors":"M. K. Volkov,&nbsp;A. A. Pivovarov,&nbsp;K. Nurlan","doi":"10.1140/epja/s10050-025-01531-7","DOIUrl":"10.1140/epja/s10050-025-01531-7","url":null,"abstract":"<div><p>In the <span>(U(3) times U(3))</span> quark NJL model, <span>(tau )</span> lepton decays with the production of scalar mesons <span>(f_0(pi ,K))</span> and neutrinos are studied, where <span>(f_0=f_0(500), f_0(980))</span>. It is shown that these decays mainly occur via contact channels and channels with axial-vector mesons <span>(a_1(1260))</span>, <span>(K_1(1270))</span> and <span>(K_1(1400))</span>. All mesons are considered as quark-antiquark states in this case. The obtained results can be considered as predictions for future experiments. The obtained estimates for the branching fractions of the <span>(tau rightarrow pi ^-2pi ^0 nu _tau )</span> decay taking into account the contributions of the <span>(rho pi )</span> and <span>(f_0(500)pi )</span> states are in satisfactory agreement with experimental data.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 3","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of multiple anti-magnetic rotational bands in (^{106})Cd","authors":"Diwanshu,&nbsp;Ashok Kumar,&nbsp;Bharti Rohila,&nbsp;Chetan Sharma,&nbsp; Subodh,&nbsp;Ishika Sharma,&nbsp;P. S. Rawat,&nbsp;Anand Pandey,&nbsp;Kaushik Katre,&nbsp;H. Arora,&nbsp;U. S. Ghosh,&nbsp; Yashraj,&nbsp;C. Majumder,&nbsp;H. P. Sharma,&nbsp;S. K. Chamoli,&nbsp;S. Kumar,&nbsp;S. Muralithar,&nbsp;R. P. Singh","doi":"10.1140/epja/s10050-025-01525-5","DOIUrl":"10.1140/epja/s10050-025-01525-5","url":null,"abstract":"<div><p>Lifetimes of excited states of positive and negative parity <span>(Delta )</span>I = 2 bands of <span>(^{106})</span>Cd have been measured using the Doppler Shift Attenuation Method (DSAM). The electric quadrupole reduced transition probability rates, B(E2), show a significant decreasing trend with increasing spin along with large observed <span>(Im ^{(2)})</span>/B(E2) values. The experimental observations, interpreted in the framework of semiclassical particle-rotor model (SCM) calculations, suggest that these bands have the character of twin-shears type anti-magnetic rotational bands resulting from the coupling of g<span>(_{9/2})</span> proton holes with h<span>(_{11/2})</span>, g<span>(_{9/2})</span> and d<span>(_{5/2})</span> neutron particles. Another negative-parity band in the same nucleus has been studied using SCM, which also interprets it to be an anti-magnetic rotational band.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 3","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143716981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Detectors and front-end electronics for nuclear physics research at IUAC","authors":"Akhil Jhingan,&nbsp;E. T. Subramaniam,&nbsp;S. Venkataramanan","doi":"10.1140/epja/s10050-025-01526-4","DOIUrl":"10.1140/epja/s10050-025-01526-4","url":null,"abstract":"<div><p>We review the developmental activities in the field of radiation detectors and coupled instrumentation/electronics at IUAC (formerly NSC). The facility focuses on nuclear reaction and structure studies around the Coulomb barrier using ion beams from the accelerator. To execute these experiments, IUAC has a detector development program for preparing detector systems based on position sensitive fast timing proportional/avalanche counters, particle identification detectors such as segmented ionization chambers, hybrid gas-silicon telescopes, segmented and resistive position sensitive silicon detectors, and scintillators for light-charged particle, neutron and γ-<i>ray</i> detection, and germanium detectors for high resolution γ-<i>ray</i> spectroscopy. This is further exalted by a strong front-end electronics development program for detector signal processing. Different types of stand-alone and multi-channel low noise preamplifiers (charge sensitive and fast timing), spectroscopy amplifiers, discriminators, logic units, etc. have been developed. Customized high resolution analog to digital converters, trigger generator cum event identifier module for handling trigger signals for multi-detector arrays, crate controllers, synchronizing and time stamping units have been developed in CAMAC as well as VME standards for the data acquisition system. This nuclear instrumentation has been routinely used to perform experiments of fusion and fusion-fission dynamics, and nuclear spectroscopy using the facilities of recoil mass spectrometers, scattering chamber, neutron and gamma detector arrays etc. New detector systems are being planned and developed for these facilities as well as for the future international facilities such as NUSTAR. This article describes an overview of detector instrumentation activities.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 3","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epja/s10050-025-01526-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143706975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of centrifugal potential on (alpha ) decay properties","authors":"Jia-Jia Liu,&nbsp;Shi-Hui Cheng,&nbsp;Wen-Ting Wu,&nbsp;Feng-Shou Zhang","doi":"10.1140/epja/s10050-025-01541-5","DOIUrl":"10.1140/epja/s10050-025-01541-5","url":null,"abstract":"<div><p>The centrifugal potential has a significant impact on the total potential of the <span>(alpha )</span> decay system. But it is always ignored in many models and semi-empirical formulas. In this work, an improved semi-empirical formula including the contribution of centrifugal potential for <span>(alpha )</span> decay half-lives has been proposed based on the Wentzel–Kramers–Brillouin (WKB) barrier penetration. Compared to other semi-classical formulas, the formula in this work has the smallest standard deviation. By using this formula, the <span>(alpha )</span> decay half-lives of even–even and odd-A nuclei with atomic numbers <i>Z</i> = 117, 118, 119, and 120 are predicted. The calculated <span>(alpha )</span> decay half-lives of ²⁹³Ts and ²⁹⁴Og exhibit good agreement with experimental measurements. The characteristics of predicted <span>(alpha )</span> decay energy and half-lives indicate that <i>N</i> = 184 is the next neutron magic number after <i>N</i> = 126. Finally, the competition between <span>(alpha )</span> decay and spontaneous fission is investigated. The decay modes for isotopes ^289–317Ts, ^290–318Og, ^291–319119, and ^292–320120 are also shown.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 3","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epja/s10050-025-01541-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143706933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atomic input for modeling ionic mixtures in astrophysical plasma","authors":"S. Fritzsche","doi":"10.1140/epja/s10050-025-01535-3","DOIUrl":"10.1140/epja/s10050-025-01535-3","url":null,"abstract":"<div><p>Accurate atomic data are known as a key ingredient for modeling the physical behavior of a wide range of plasma throughout the universe. When these data are combined with simulations of ionic mixtures, they (may) help infer the temperature, electron density, and ionization state of the plasma under non-ideal plasma conditions. We here report about an expansion of JAC, the Jena Atomic Calculator, in order to encourage the modeling of ionic mixtures and their thermodynamic properties under different plasma conditions. Whereas emphasis has first been placed upon simulations of ionic compositions in (ideal) local thermodynamic equilibrium, various features are prepared in this code to account for non-ideal conditions, such as plasma screening contributions, the ionization potential depression (IPD) or some non-classical statistics. To demonstrate these features of JAC, we have calculated the mean charge and charge-state distribution of a hot carbon plasma as well as some ionic mixture from the sun’s photosphere at selected temperatures <i>T</i> and mass densities <span>(rho _m)</span>. These computations show a significant shift in the mean charge distribution, if the IPD is incorporated by means of a Stewart–Pyatt plasma model. Since the JAC toolbox is based on Dirac’s relativistic equation, the present expansion of the code will facilitate also the treatment of ionic mixtures with medium and heavy elements as relevant for neutron-star mergers and elsewhere.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 3","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epja/s10050-025-01535-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143706952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Magnetic dipole moments of the singly-heavy baryons with spin-(frac{1}{2}) and spin-(frac{3}{2})","authors":"Ulaş Özdem","doi":"10.1140/epja/s10050-025-01536-2","DOIUrl":"10.1140/epja/s10050-025-01536-2","url":null,"abstract":"<div><p>The electromagnetic characteristics of singly-heavy baryons at low energies are responsive to their internal composition, structural configuration, and the associated chiral dynamics of light diquarks. To gain further insight, experimentalists attempt to measure the magnetic dipole moments of singly-charm baryons at the LHC. Given these developments, we conducted an extensive analysis of the magnetic dipole moments of both <span>(mathrm{J^P}=frac{1}{2}^+)</span> and <span>(mathrm{J^P}=frac{3}{2}^+)</span> singly-heavy baryons employing the QCD light-cone sum rules. Our findings have been compared with other phenomenological estimations that could prove a valuable supplementary resource for interpreting the singly-heavy baryon sector. To shed light on the internal structure of these baryons we study the contributions of the individual quark sectors to the magnetic dipole moments. It was observed that the magnetic dipole moments of the spin-<span>(frac{1}{2})</span> sextet singly-heavy baryons are governed by the light quarks. Conversely, the role of the heavy quark is significantly enhanced for the spin-<span>(frac{1}{2})</span> anti-triplet and spin-<span>(frac{3}{2})</span> sextet singly-heavy baryons. The contribution of light and heavy quarks is observed to have an inverse relationship. The signs of the magnetic dipole moments demonstrate the interaction of the spin degrees of freedom of the quarks. The opposing signs of the light and heavy-quark magnetic dipole moments imply that the spins of these quarks are anti-aligned concerning each other in the baryon. As a byproduct, the electric quadrupole and magnetic octupole moments of spin-<span>(frac{3}{2})</span> singly-heavy baryons are also calculated. We ascertained the existence of non-zero values for the electric quadrupole and magnetic octupole moments of these baryons, indicative of a non-spherical charge distribution.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 3","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epja/s10050-025-01536-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143706954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}