Fri·May 16, 2025Friday·May 16, 2025

1. 01*

   Cross-section of the ${}^{\mathrm{nat}}\mathrm{Ni}(\gamma ,\mathrm{p}x\mathrm{n}{)}^{58}\mathrm{Co}$ reaction at the bremsstrahlung end-point energy of 35-94 MeV

   I.S. Timchenko🇸🇰 · O.S. Deiev🇺🇦 · S.M. Olejnik🇺🇦 · S.M. Potin🇺🇦 · V.A. Kushnir🇺🇦 · V.V. Mytrochenko🇺🇦 · S.A. Perezhogin🇺🇦 · A. Herzáň🇸🇰

   The photoproduction of the ${}^{58}\mathrm{Co}$ nuclei on ${}^{\mathrm{nat}}\mathrm{Ni}$ was studied using the induced $\gamma$-activity method and off-line $\gamma$-ray spectrometric technique. The experiment was performed at the electron linear accelerator LUE-40 NSC KIPT, Ukraine. The total flux-averaged cross-section $⟨\sigma (E_{\gamma \max })⟩$ for the ${}^{\mathrm{nat}}\mathrm{Ni}(\gamma ,\mathrm{p}x\mathrm{n}{)}^{58}\mathrm{Co}$ reaction has been measured in the range of bremsstrahlung end-point energies $E_{\gamma \max }$ = 35-94 MeV. The obtained $⟨\sigma (E_{\gamma \max })⟩$ were compared with theoretical estimates. The theoretical values of $⟨\sigma (E_{\gamma \max }){⟩}_{\mathrm{th}}$ were calculated using the partial cross-sections $\sigma (E)$ from the TALYS1.96 code for different level density models and gamma strength functions.

   nucl-exhep-exEPJA(2025)·0 citations
2. 02*

   Competition between the neutron-proton pair break-ups delineating the level structure of 202Po

   Sahab Singh🇮🇳 · D. Choudhury🇳🇱 · B. Maheshwari🇫🇷 · R. Roy🇮🇳 · K. Yadav🇮🇳 · R. Palit🇮🇳 · B. Das🇮🇳 · P. Dey🇮🇳 · A. Kundu🇮🇳 · Md. S. R. Laskar🇮🇳 · D. Negi🇮🇳 · V. Malik🇮🇳 and 9 other authors

   High-spin spectroscopic study of ${}^{202}$Po ($Z$ = 84, $N$ = 118) has been carried out using the ${}^{195}$Pt(${}^{12}$C, 5n)${}^{202}$Po fusion-evaporation reaction. An extended level scheme has been proposed up to an excitation energy of $E_x\approx$ 8 MeV and angular momentum of 27$\hslash$, with the addition of 57 newly observed $\gamma$-ray transitions, along with the revisions in the placement of 8 already known transitions and the multipolarities of 4 of these transitions. The energy of the unobserved 8${}^{+}\to 6^{+}$ transition has been proposed to be 9.0(5) keV, which resolves the uncertainty in the excitation energy of the levels above the 6${}^{+}$ state. Three new sequences of $M1$ transitions have also been identified in the high excitation energy regime and included in the proposed level scheme. The large-scale shell model calculations for $Z>82$ and $N<126$ valence space have been carried out using PBPOP interaction which explained the overall level scheme for both the positive and negative parity states. The calculations successfully reproduced the purity of the proton $\pi h_{9/2}$ dominated $8^{+}$ isomeric state, and also explained the missing $E2$ decay of the ${12}^{+}$ isomeric state in terms of changing nucleonic configurations.

   nucl-exnucl-thPRC(2025)·1 citation
3. 03*

   Future facilities: the CERN SPS

   Roberta Arnaldi🇮🇹

   The Super Proton Synchrotron (SPS) at CERN has played a pioneering role in the study of heavy-ion collisions since 1986 and nowadays remains central to the exploration of the Quark Gluon Plasma. This document summarizes the present status and future prospects of the SPS physics program with particular focus on hard and electromagnetic probes, highlighting the results and goals of NA61/SHINE and the proposed NA60+ experiment.

   nucl-exEPJ Web Conf.(2025)·4 citations
4. 04*

   Correlations of $Q_{\beta }$-values with symmetry energy and effective mass studied within Skyrme energy--density functionals

   Futoshi Minato🇯🇵 · Yifei Niu🇨🇳 · Kenichi Yoshida🇯🇵

   The $\beta$-decay half-lives of nuclei are sensitive to the values of $Q_{\beta }$. For accurate theoretical predictions, it is essential to develop an effective interaction or an energy density functional (EDF) that can systematically reproduce experimental $Q_{\beta }$ values. The challenge lies in identifying an appropriate EDF for an accurate $Q_{\beta }$ prediction. To address this, we focus on the bulk properties of nuclei that have correlations with $Q_{\beta }$. The primary objective of this study is to determine which nuclear bulk properties are sensitive to $Q_{\beta }$, providing information on the key nuclear characteristics that influence $\beta$-decay calculations. We employ the Skyrme energy-density functionals to find correlations between $Q_{\beta }$ and the nuclear bulk properties, assuming spherical symmetry. Using $42$ different Skyrme EDFs, we analyze these correlations by evaluating Pearson linear coefficients, focusing particularly on the relationship between $Q_{\beta }$ and various nuclear properties. We found that the symmetry energy at low densities shows a correlation with the $Q_{\beta }$ value. In particular, this correlation becomes stronger for functionals with an effective mass close to $1$. However, as the nuclear density increases, the correlation weakens. From our analysis, we found that a symmetry energy of $32.8\pm 0.7$~MeV and effective mass of $m^{\ast }/m\ge 0.75$ at the saturation density is the most likely to systematically reproduce the experimental data of $Q_{\beta }$ systematically.

   ↳ nucl-thnucl-exPRC(2025)·0 citations
5. 05*

   Comparative Analysis of Richardson-Lucy Deconvolution and Data Unfolding with Mean Integrated Square Error Optimization

   Nikolay D. Gagunashvili

   Two maximum likelihood-based algorithms for unfolding or deconvolution are considered: the Richardson-Lucy method and the Data Unfolding method with Mean Integrated Square Error (MISE) optimization [10]. Unfolding is viewed as a procedure for estimating an unknown probability density function. Both external and internal quality assessment methods can be applied for this purpose. In some cases, external criteria exist to evaluate deconvolution quality. A typical example is the deconvolution of a blurred image, where the sharpness of the restored image serves as an indicator of quality. However, defining such external criteria can be challenging, particularly when a measurement has not been performed previously. In such instances, internal criteria are necessary to assess the quality of the result independently of external information. The article discusses two internal criteria: MISE for the unfolded distribution and the condition number of the correlation matrix of the unfolded distribution. These internal quality criteria are applied to a comparative analysis of the two methods using identical numerical data. The results of the analysis demonstrate the superiority of the Data Unfolding method with MISE optimization over the Richardson-Lucy method.

   ↳ physics.data-anastro-ph.IMhep-exnucl-ex+1Comput.Phys.Commun.(2026)·1 citation
6. 06*

   Facility based on electron linac LUE-40 -- current state and main research directions

   M.I. Ayzatsky🇺🇦 · V.M Boriskin🇺🇦 · I. O. Chertishchev🇺🇦 · O.S. Deiev🇺🇦 · K.Yu. Kramarenko🇺🇦 · V.A. Kushnir🇺🇦 · V.V. Mytrochenko🇺🇦 · S.M. Olejnik🇺🇦 · S.O. Perezhogin🇺🇦 · S.M. Potin🇺🇦 · L.I. Selivanov🇺🇦 · I.S. Timchenko🇸🇰 and 3 other authors

   The paper describes the state of the installation based on the linear accelerator LUE-40 after restoration in 2023. Additional devices have been developed and created to conduct nuclear physics research. The main beam parameters are given. The electron energy range has been expanded and is currently 16-95 MeV with an average beam current of up to 6 $\mu$A. The main areas of scientific research are described and the results are presented.

   ↳ physics.acc-phnucl-exProb.Atomic Sci.Technol.(2025)·0 citations
7. 07*

   First Results on the Search for Lepton Number Violating Neutrinoless Double Beta Decay with the LEGEND-200 Experiment

   H. Acharya🇺🇸 · N. Ackermann🇩🇪 · M. Agostini🇬🇧 · A. Alexander🇬🇧 · C. Andreoiu🇨🇦 · G.R. Araujo🇨🇭 · F.T. Avignone III🇺🇸 · M. Babicz🇨🇭 · W. Bae🇺🇸 · A. Bakalyarov🇷🇺 · M. Balata🇮🇹 · A.S. Barabash🇷🇺 and 247 other authors

   The LEGEND collaboration is searching for neutrinoless double beta ($0\nu \beta \beta$) decay by operating high-purity germanium detectors enriched in ${}^{76}$Ge in a low-background liquid argon environment. Building on key technological innovations from GERDA and the MAJORANA DEMONSTRATOR, LEGEND-200 has performed a first $0\nu \beta \beta$ decay search based on 61.0 kg yr of data. Over half of this exposure comes from our highest performing detectors, including newly developed inverted-coaxial detectors, and is characterized by an estimated background level of $0.5_{-0.2}^{+0.3}$ cts/(keV kg yr) in the $0\nu \beta \beta$ decay signal region. A combined analysis of data from GERDA, the MAJORANA DEMONSTRATOR, and LEGEND-200, characterized by a 90% confidence level exclusion sensitivity of $2.8\times 10^{26}$ yr on the half-life of $0\nu \beta \beta$ decay, reveals no evidence for a signal and sets a new observed lower limit at $T_{1/2}^{0\nu }>1.9\times 10^{26}$ yr (90% confidence level). Assuming the decay is mediated by Majorana neutrinos, this corresponds to an upper limit on the effective Majorana mass in the range $m_{\beta \beta }<75-200$ meV, depending on the adopted nuclear matrix element.

   ↳ hep-exnucl-exPRL(2026)·71 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.