I. S. Timchenko, O. S. Deiev, S. M. Olejnik, S. M. Potin, V. A. Kushnir, V. V. Mytrochenko, S. A. Perezhogin, A. Herzáň
{"title":"Cross-section of the ({^textrm{nat}textrm{Ni}}(gamma ,textrm{p} xtextrm{n})^{58}textrm{Co}) reaction at the bremsstrahlung end-point energy of 35–94 MeV","authors":"I. S. Timchenko, O. S. Deiev, S. M. Olejnik, S. M. Potin, V. A. Kushnir, V. V. Mytrochenko, S. A. Perezhogin, A. Herzáň","doi":"10.1140/epja/s10050-025-01666-7","DOIUrl":"10.1140/epja/s10050-025-01666-7","url":null,"abstract":"<div><p>The photoproduction of the <span>(^{58}textrm{Co})</span> nuclei on <span>({^textrm{nat}textrm{Ni}})</span> was studied using the induced <span>(gamma )</span>-activity method and offline <span>(gamma )</span>-ray spectrometric technique. The experiment was performed at the electron linear accelerator LUE-40 of NSC KIPT, Ukraine. The total flux-averaged cross-section <span>(langle {sigma (E_{gamma textrm{max}})}rangle )</span> for the <span>({^textrm{nat}textrm{Ni}}(gamma ,textrm{p} xmathrm n)^{58}textrm{Co})</span> reaction has been measured in the range of bremsstrahlung end-point energies <span>(E_{gamma textrm{max}})</span> = 35–94 MeV. The obtained <span>(langle {sigma (E_{gamma textrm{max}})}rangle )</span> were compared with theoretical estimates, and with experimental data found in the literature. The theoretical values of <span>(langle {sigma (E_{gamma textrm{max}})}rangle _textrm{th})</span> were calculated using the partial cross-sections <span>(sigma (E))</span> from the TALYS1.96 code for different level density models and gamma strength functions.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 9","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epja/s10050-025-01666-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144990537","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}
Sameer Ahmad Mir, Saeed Uddin, Swatantra Kumar Tiwari
{"title":"Influence of excluded volume corrections on hadronic yield in high-energy nuclear collisions","authors":"Sameer Ahmad Mir, Saeed Uddin, Swatantra Kumar Tiwari","doi":"10.1140/epja/s10050-025-01667-6","DOIUrl":"10.1140/epja/s10050-025-01667-6","url":null,"abstract":"<div><p>This article presents a comprehensive study of various particle ratios involving strange and non-strange hadrons across a wide range of center-of-mass energies from the lowest energies at the Relativistic Heavy Ion Collider (RHIC) to the highest at the Large Hadron Collider (LHC). We utilize the excluded-volume hadron resonance gas (EV-HRG) model to calculate these ratios, assigning a hard-core size to each baryon and anti-baryon to account for repulsive interactions. To explore potential differences in the production mechanisms of strange versus non-strange hadrons, we incorporate a strangeness suppression factor (<span>(gamma _s)</span>) into our formulation. Additionally, we compare our results with those obtained from other theoretical approaches, including the van der Waals (vdW) model, transport models such as the A Multi-Phase Transport (AMPT) model and the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) model, as well as from effective theory frameworks like the Nambu–Jona–Lasinio (NJL) model. Our analysis shows that a baryon and anti-baryon hard-core radius of 0.59 fm provides a good fit to the experimental data. Overall, this study highlights the strengths and predictive accuracy of various statistical thermal, transport, and effective theory models, with the EV-HRG model demonstrating particularly strong agreement with experimental observations.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144914762","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":"Experimental studies of the microscopic structure of the pygmy dipole resonance and comments on a possible pygmy quadrupole resonance","authors":"M. Spieker","doi":"10.1140/epja/s10050-025-01669-4","DOIUrl":"10.1140/epja/s10050-025-01669-4","url":null,"abstract":"<div><p>The pygmy dipole resonance (PDR) has been observed on the low-energy tail of the isovector giant dipole resonance (IVGDR) below and above the neutron-separation threshold. While the additional strength is recognized as a feature of the electric dipole response of many nuclei with neutron excess, its microscopic structure, which intimately determines its contribution to the overall strength, is still poorly understood. This makes reliable predictions of the PDR in neutron-rich nuclei far off stability difficult. It has been shown that the coupling to complex configurations drives the strength fragmentation for both the IVGDR and the PDR, and that more strength gets fragmented to lower energies when including such configurations. The wavefunctions of <span>(J^{pi }= 1^-)</span> states belonging to the PDR are, however, expected to be dominated by one-particle-one-hole (1p-1h) excitations of the excess neutrons. First experiments were performed to access these parts of the wavefunction via inelastic proton scattering through isobaric analog resonances and via one-neutron transfer reactions. The results, obtained from these experiments, will be discussed in this contribution and some new results added. Given the special occasion of Professor Bracco’s university retirement, I will also comment on experimental studies of a possible pygmy quadrupole resonance (PQR).</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144897053","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":"On the possible existence of a (S=-3), (I=1) pentaquark","authors":"Albert Feijoo, Isaac Vidaña","doi":"10.1140/epja/s10050-025-01664-9","DOIUrl":"10.1140/epja/s10050-025-01664-9","url":null,"abstract":"<div><p>In this exploratory work we analyze the possible existence of a strangeness <span>(S=-3)</span>, isospin <span>(I=1)</span> pentaquark state <span>(P_{sss})</span> generated dynamically from the <span>(bar{K}Xi )</span> interaction. We employ a unitarized scheme in coupled channels based on the chiral Lagrangian expanded up to next-to-leading order (NLO), and show that the inclusion of the NLO terms can be crucial to provide the necessary attraction that favors the existence of such triply strange pentaquark. The <span>(bar{K}Xi )</span> femtoscopic correlation functions are calculated as example of a possible experimental measurement in which a direct signal of the <span>(P_{sss})</span> state could be observed.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144892444","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":"Investigating the (mathbf {text {p--}uppi ^{pm }}) and (mathbf {text {p--p--}uppi ^{pm }}) dynamics with femtoscopy in pp collisions at (mathbf {sqrt{textit{s}}=13}) TeV","authors":"ALICE Collaboration","doi":"10.1140/epja/s10050-025-01615-4","DOIUrl":"10.1140/epja/s10050-025-01615-4","url":null,"abstract":"<div><p>The interaction between pions and nucleons plays a crucial role in hadron physics. It represents a fundamental building block of the low-energy QCD dynamics and is subject to several resonance excitations. This work studies the <span>(text {p--}uppi ^{pm })</span> dynamics using femtoscopic correlations in high-multiplicity pp collisions at <span>(sqrt{s} = 13)</span> TeV measured by ALICE at the LHC. As the final-state interaction between protons and pions is well constrained by scattering experiments and the study of pionic hydrogen, the results give access to information on the particle-emitting source in pp collisions using the femtoscopy methods. The scaling of the source size of primordial protons and pions against their pair transverse mass is extracted. The results are compared with the source sizes studied with p–p, <span>(text {p--K}^+)</span>, and <span>(uppi ^pm )</span>–<span>(uppi ^pm )</span> pairs by ALICE in the same collision system and are found to be in agreement for the different particle pairs. This reinforces recent findings by ALICE of a common emission source for all hadron-pairs in pp collisions at LHC energies. Furthermore, the <span>(text {p--p--}uppi ^{pm })</span> systems are studied using three-particle femtoscopy in pp collisions at <span>(sqrt{s} = 13)</span> TeV. The presence of three-body effects is analyzed utilizing the cumulant expansion method. In this formalism, the known two-body interactions are subtracted in order to isolate the three-body effects. For both, <span>(text {p--p--}uppi ^{+})</span> and <span>(text {p--p--}uppi ^{-})</span>, a non-zero cumulant is found, indicating effects beyond pairwise interactions. These results give information on the coupling of the pion to multiple nucleons.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epja/s10050-025-01615-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144869138","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}
S. Chen, S. Paschalis, M. Petri, M. A. Bentley, M. Labiche, S. Heil, F. Holloway
{"title":"Development of the self-calibration technique for (gamma )-ray energy tracking arrays","authors":"S. Chen, S. Paschalis, M. Petri, M. A. Bentley, M. Labiche, S. Heil, F. Holloway","doi":"10.1140/epja/s10050-025-01651-0","DOIUrl":"10.1140/epja/s10050-025-01651-0","url":null,"abstract":"<div><p>Determining the three-dimensional <span>(gamma )</span>-ray interaction position in <span>(gamma )</span>-ray tracking arrays is achieved by comparing in real time the measured electronic signals against a pre-generated library of calculated signals (signal basis) that maps the detector response throughout the crystal volume. Obtaining a high-fidelity signal basis remains a significant technological challenge that often limits the ultimate performance of the arrays. To address this, a self-calibration method was proposed to generate the signal basis experimentally, in an iterative way and in situ; its potential has been demonstrated in a proof-of-concept study using a simplistic geometry. In this article, we extend and refine this innovative technique for <span>(gamma )</span>-ray tracking arrays using realistic simulations of the actual crystal geometries and including pulse-shape analysis that mimics the reconstruction that takes place experimentally. Key factors determining the performance of the method, such as the conditions for position convergence, statistical requirements, the impact of convoluting electronic noise to the signals, and the time alignment are investigated systematically within this framework. The results show that the method is robust and holds promise for generating high-fidelity signal basis experimentally. The analysis framework established in this work sets the stage for applying the self-calibration technique to real experimental data.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144880866","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}
Ranjith Mudimadugula, Federico Schianchi, Anna Neuweiler, Thibeau Wouters, Henrique Gieg, Tim Dietrich
{"title":"Employing deep-learning techniques for the conservative-to-primitive recovery in binary neutron star simulations","authors":"Ranjith Mudimadugula, Federico Schianchi, Anna Neuweiler, Thibeau Wouters, Henrique Gieg, Tim Dietrich","doi":"10.1140/epja/s10050-025-01661-y","DOIUrl":"10.1140/epja/s10050-025-01661-y","url":null,"abstract":"<div><p>The detection of GW170817, together with its electromagnetic counterparts, has proven that binary neutron star mergers are of central importance to the field of nuclear astrophysics, e.g., through a better understanding of the formation of elements and novel constraints on the supranuclear dense equation of state governing the matter inside neutron stars. Essential for understanding the binary coalescence are numerical-relativity simulations, which typically come with high computational costs requiring high-performance computing facilities. In this work, we build on recent studies to investigate whether novel techniques, such as neural networks, can be employed in the conversion of conservative variables to primitive hydrodynamical variables, such as pressure and density. In this regard, we perform – to the best of our knowledge – the first binary neutron star merger simulations in which such methods are employed. We show that this method results in stable simulations, reaching accuracies similar to traditional methods with an overall comparable computational cost. These simulations serve as a proof of principle that, in the future, deep learning techniques could be used within numerical-relativity simulations. However, further improvements are necessary to offer a computational advantage compared to traditional methods.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epja/s10050-025-01661-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144869139","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":"Theoretical models for exotic nuclei (2nd edition)","authors":"Hiroyuki Sagawa, Kouichi Hagino","doi":"10.1140/epja/s10050-025-01641-2","DOIUrl":"10.1140/epja/s10050-025-01641-2","url":null,"abstract":"<div><p>This article is a new edition of the review paper which we published in 2015 (Sagawa and Hagino in Eur Phys J A 51:102, 2015). We particularly summarize many developments in physics of exotic nuclei after we published the previous review article. This includes recent theoretical developments in the density functional theory, the three-body model, ab-initio approaches, and machine learnings, as well as new experimental findings such as tetra neutrons, knock-out reactions of halo nuclei, 4-neutron decays of <span>(^{28})</span>O, the Coulomb breakup of <span>(^{19})</span>B, and <span>(beta )</span>-decays of nuclei relevant to r-process nucleosynthesis. We also cover halo and related topics in other disciplines, such as Efimov physics in cold atoms and halos in hypernuclei.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144929325","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}
A. Compagnucci, A. Formicola, M. Campostrini, J. Cruz, M. Aliotta, C. Ananna, L. Barbieri, F. Barile, D. Bemmerer, A. Best, A. Boeltzig, C. Broggini, C. G. Bruno, A. Caciolli, F. Casaburo, F. Cavanna, G. F. Ciani, P. Colombetti, P. Corvisiero, L. Csedreki, T. Davinson, R. Depalo, A. Di Leva, Z. Elekes, F. Ferraro, Zs. Fülöp, A. Guglielmetti, C. Gustavino, Gy. Gyürky, G. Imbriani, M. Junker, M. Lugaro, P. Marigo, J. Marsh, E. Masha, R. Menegazzo, V. Paticchio, D. Piatti, P. Prati, D. Rapagnani, V. Rigato, D. Robb, L. Schiavulli, R. S. Sidhu, J. Skowronski, O. Straniero, T. Szücs, S. Turkat, S. Zavatarelli
{"title":"Towards a comprehensive study of the (^{14})N(p,(gamma ))(^{15})O astrophysical key reaction: Description of the experimental technique including novel target preparation","authors":"A. Compagnucci, A. Formicola, M. Campostrini, J. Cruz, M. Aliotta, C. Ananna, L. Barbieri, F. Barile, D. Bemmerer, A. Best, A. Boeltzig, C. Broggini, C. G. Bruno, A. Caciolli, F. Casaburo, F. Cavanna, G. F. Ciani, P. Colombetti, P. Corvisiero, L. Csedreki, T. Davinson, R. Depalo, A. Di Leva, Z. Elekes, F. Ferraro, Zs. Fülöp, A. Guglielmetti, C. Gustavino, Gy. Gyürky, G. Imbriani, M. Junker, M. Lugaro, P. Marigo, J. Marsh, E. Masha, R. Menegazzo, V. Paticchio, D. Piatti, P. Prati, D. Rapagnani, V. Rigato, D. Robb, L. Schiavulli, R. S. Sidhu, J. Skowronski, O. Straniero, T. Szücs, S. Turkat, S. Zavatarelli","doi":"10.1140/epja/s10050-025-01658-7","DOIUrl":"10.1140/epja/s10050-025-01658-7","url":null,"abstract":"<div><p>While the <span>(^{14})</span>N(p,<span>(gamma )</span>)<span>(^{15})</span>O reaction plays a key role in the hydrogen-burning processes in various stellar conditions, its reaction rate is not known with sufficient precision. Therefore, the first scientific project at the recently launched Bellotti Ion Beam Facility of the Laboratori Nazionali del Gran Sasso was the measurement of the <span>(^{14})</span>N(p,<span>(gamma )</span>)<span>(^{15})</span>O reaction cross section in the proton energy range between 250 and 1500 keV. In this paper, the experimental techniques are summarized with special emphasis on the description of solid state nitrogen target production and characterization. The first results of the reaction yield measured at 55<span>(^circ )</span> detection angle are also presented.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epja/s10050-025-01658-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144853646","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":"Precision measurement of the half-lifes of the excited nuclear states in Fe-57","authors":"Benedikt Bergmann, Lukas Javora, Petr Smolyanskiy","doi":"10.1140/epja/s10050-025-01659-6","DOIUrl":"10.1140/epja/s10050-025-01659-6","url":null,"abstract":"<div><p>The half-lifes of the nuclear isomeric states in <sup>57</sup>Fe at 14.4 keV and 136.5 keV above the ground state are measured with unprecedented precision using hybrid pixel detectors based on Timepix3 technology. These detectors enable dead-time-free single-photon detection and provide simultaneous measurements of photon energy and arrival time, allowing for nanosecond-scale determination of time differences between characteristic X-rays and <span>(gamma )</span>-rays emitted during the electron-capture decay of <sup>57</sup>Co. Employing the delayed coincidence technique, the half-life of the 14.4-keV state is determined as <span>(t^{14.4 text { keV}}_{1/2} = 97.82(5))</span> ns, achieving a fourfold improvement in precision over previous measurements. The half-life of the 136.5-keV state is measured as <span>(t^{136 text { keV}}_{1/2}= 8.730(17))</span> ns, reducing the uncertainty by a factor of two. These results are discussed in the context of previous works.</p></div>","PeriodicalId":786,"journal":{"name":"The European Physical Journal A","volume":"61 8","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1140/epja/s10050-025-01659-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144843339","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}