Tue·Nov 19, 2024Tuesday·November 19, 2024

1. 01*

   Large quadrupole deformation in ${}^{20}$Ne challenges rotor model and modern theory: urging for $\alpha$ clusters in nuclei

   C. V. Mehl🇿🇦 · J. N. Orce🇿🇦 · C. Ngwetsheni🇿🇦 · P. Marević🇭🇷 · B. A. Brown🇺🇸 · J. D. Holt🇨🇦 · M. Kumar Raju🇿🇦 · E. A. Lawrie🇿🇦 · K. J. Abrahams🇿🇦 · P. Adsley🇿🇦 · E. H. Akakpo🇿🇦 · R. A. Bark🇿🇦 and 22 other authors

   The spectroscopic quadrupole moment of the first excited state, $Q_{{}_S}(2_1^{+})$, at 1.634 MeV in ${}^{20}$Ne was determined from sensitive reorientation-effect Coulomb-excitation measurements using a heavy target and safe energies well below the Coulomb barrier. Particle-$\gamma$ coincidence measurements were collected at iThemba LABS with a digital data-acquisition system using the {\sc AFRODITE} array coupled to an annular, doubled-sided silicon detector. A precise value of $Q_{{}_S}(2_1^{+})=-0.22(2)$ eb was determined at backward angles in agreement with the only safe-energy measurement prior to this work, $Q_{{}_S}(2_1^{+})=-0.23(8)$ eb. This result adopts 1$\hslash \omega$ shell-model calculations of the nuclear dipole polarizability of the 2${}_1^{+}$ state that contributes to the effective quadrupole interaction and determination of $Q_{{}_S}(2_1^{+})$. It disagrees, however, with the ideal rotor model for axially-symmetric nuclei by almost $3\sigma$. Larger discrepancies are computed by modern state-of-the-art calculations performed in this and prior work, including {\it ab initio} shell model with chiral effective interactions and the multi-reference relativistic energy density functional ({\sc MR-EDF}) model. The intrinsic nucleon density of the 2${}_1^{+}$ state in ${}^{20}$Ne calculated with the {\sc MR-EDF} model illustrates the presence of $\alpha$ clustering, which explains the largest discrepancy with the rotor model found in the nuclear chart and motivates the explicit inclusion of $\alpha$ clustering for full convergence of $E2$ collective properties.

   nucl-exhep-exnucl-thPRC(2025)·2 citations
2. 02*

   Neutron skin thickness for ${}^{208}$Pb from total cross sections of neutron scattering at 14.137 MeV and neutron skin thickness for ${}^{48}$Ca, O, N, C isotopes from reaction and interaction cross sections

   Shingo Tagami🇯🇵 · Takayuki Myo🇯🇵 · Masanobu Yahiro🇯🇵

   Foster {\it et al.} measured total neutron cross sections ${\sigma }_{\mathrm{T}}$ of n+${}^{208}$Pb scattering at $14.137$MeV. Carlson {\it et al.} measured ${\sigma }_{\mathrm{R}}$ for $p$+${}^{48}$Ca scattering in $23\text{–}48$MeV. Tanaka {\it et al.} measured ${\sigma }_{\mathrm{I}}$ for ${}^{42\text{–}51}$Ca + ${}^{12}$C scattering at 280MeV/u. Bagchi {\it et al.} measured the charge-changing (CC) cross sections and determined proton radii $r_{\mathrm{p}}(\mathrm{CC})$ for ${}^{14,15,17\text{–}22}$N from the CC cross sections. Kanungo {\it et al.} measured the CC cross sections and extracted $r_{\mathrm{p}}(\mathrm{CC})$ for ${}^{12\text{–}19}$C. Kaur {\it et al.} measured the CC cross sections and determined $r_{\mathrm{p}}(\mathrm{CC})$ for ${}^{16,18\text{–}24}$O. Our 1st aim is to extract $r_{\mathrm{skin}}^{208}$ from the the ${\sigma }_{\mathrm{T}}$ of n+${}^{208}$Pb scattering at $14.137$MeV. Our 2nd aim is to determine $r_{\mathrm{skin}}^{48}(\mathrm{skin})$ from ${\sigma }_{\mathrm{R}}$ on p+${}^{48}$Ca scattering in $E_{\mathrm{lab}}=23\text{–}48$MeV. Our 3rd aim is to find light stable nuclei having nuclei having large $r_{\mathrm{skin}}$. We use the Kyushu $g$-matrix folding model for lower $E_{\mathrm{lab}}$ and the folding model based on the Love-Franey $t$-matrix for higher $E_{\mathrm{lab}}$. We determine $r_{\mathrm{skin}}^{48}(\mathrm{skin})=0.163\pm 0.037\mathrm{fm}$ from the ${\sigma }_{\mathrm{R}}$ on p+${}^{48}$Ca scattering, using the Kyushu $g$-matrix folding model with the D1M-GHFB+AMP proton and neutron densities. We show that D1M-GHFB+AMP is better than D1S-GHFB+AMP for the matter radius and the binding energy. Our skin value is consistent with $r_{\mathrm{skin}}^{48}(\mathrm{CREX})$. For C, N, O isotopes, we find that $r_{\mathrm{skin}}=0.267\pm 0.056$~fm for ${}^{14}$N and $r_{\mathrm{skin}}=0.197\pm 0.067$~fm for ${}^{17}$O. Our value $r_{\mathrm{skin}}^{208}=0.309\pm 0.057$fm agrees with $r_{\mathrm{skin}}^{208}(PREX2)$.

   nucl-exPRC(2024)·1 citation
3. 03*

   Measurement of enhanced electric dipole transition strengths at high spin in ${}^{100}$Ru: Possible observation of octupole deformation

   A. Karmakar · Nazira Nazir · P. Datta🇺🇸 · J. A. Sheikh🇮🇳 · S. Jehangir🇮🇳 · G. H. Bhat🇮🇳 · S. S. Nayak · Soumik Bhattacharya🇮🇳 · Suchorita Paul · Snigdha Pal · S. Bhattacharyya🇮🇳 · G. Mukherjee🇮🇳 and 10 other authors

   The majority of atomic nuclei have deformed shapes and nearly all these shapes are symmetric with respect to reflection. There are only a few reflection asymmetric pear-shaped nuclei that have been found in actinide and lanthanide regions, which have static octupole deformation. These nuclei possess an intrinsic electric dipole moment due to the shift between the center of charge and the center of mass. This manifests in the enhancement of the electric dipole transition rates. In this article, we report on the measurement of the lifetimes of the high spin levels of the two alternate parity bands in ${}^{100}$Ru through the Doppler Shift Attenuation Method. The estimated electric dipole transition rates have been compared with the calculated transition rates using the triaxial projected shell model without octupole deformation, and are found to be an order of magnitude enhanced. Thus, the observation of seven inter-leaved electric dipole transitions with enhanced rates establish ${}^{100}$Ru as possibly the first octupole deformed nucleus reported in the A $\approx$ 100 mass region.

   nucl-exnucl-thPRC(2024)·2 citations
4. 04*

   Recent results on heavy flavours and quarkonia from ALICE

   Fiorella Fionda (on behalf of the ALICE Collaboration)🇮🇹

   Heavy-flavour hadrons, containing at least one charm or beauty quark, are excellent probes of the deconfined medium created in ultra-relativistic heavy-ion collisions, known as quark-gluon plasma. Results in smaller collision systems, such as proton-proton and p-Pb collisions, besides representing an important baseline for interpreting heavy-ion measurements, are crucial to test perturbative QCD calculations and hadronisation mechanisms in the absence of hot medium effects, as well as to search for commonalities with heavy-ion systems. Recently, measurements in proton-proton and p-Pb collisions have revealed unforeseen features with respect to the expectations based on previous results from ${\mathrm{e}}^{+}{\mathrm{e}}^{-}$ and ep collisions, showing that fragmentation fractions of heavy quarks are not universal. In this contribution, an overview of the most recent ALICE heavy-flavour measurements, along with the comparison to available calculations, will be discussed.

   nucl-exhep-exEPJ Web Conf.(2025)·0 citations
5. 05*

   Effect of the near-proton-emission threshold resonance in ${}^{11}$B on the branching ratio of beta-delayed proton emission from ${}^{11}$Be

   Nguyen Le Anh · Bui Minh Loc

   Beta-delayed proton emission from neutron halo nuclei ${}^{11}\mathrm{Be}$ represents a rare decay process. The existence of the narrow resonance near the proton-emission threshold in ${}^{11}\mathrm{B}$ explains its unexpectedly high probability. However, the accurate value of the branching ratio remains challenging to determine. We aim to quantify the influence of the narrow resonance near the proton emission threshold on the result of the branching ratio. We employ the Skyrme Hartree-Fock calculation within the potential model to obtain the branching ratio. We derive the single-particle potentials for the halo neutron and the emitting proton with minimal adjustment. Slight variations in the resonance position significantly impact the branching ratio, with the upper limit reaching the order of $10^{-5}$. Experimental determination of the resonance energy, particularly whether it lies below $200$ keV, is crucial for determining the value of the branching ratio.

   ↳ nucl-thnucl-exJ.Phys.G(2026)·0 citations
6. 06*

   Fragmentation of Nuclear Remnants in Electron-Nucleus Collisions at High Energy as a Nonextensive Process

   Ting-Ting Duan🇨🇳 · Sahanaa Büriechin🇨🇳 · Hai-Ling Lao🇨🇳 · Fu-Hu Liu🇨🇳 · Khusniddin K. Olimov🇺🇿

   Utilizing a partitioning method based on equal (or unequal) probabilities -- without incorporating the alpha-cluster ($\alpha$-cluster) model -- allows for the derivation of diverse topological configurations of nuclear fragments resulting from fragmentation. Subsequently, we predict the multiplicity distribution of nuclear fragments for specific excited nuclei, such as ${}^9$Be${}^{\ast }$, ${}^{12}$C${}^{\ast }$, and ${}^{16}$O${}^{\ast }$, which can be formed as nuclear remnants in electron-nucleus ($eA$) collisions at high energy. Based on the $\alpha$-cluster model, an $\alpha$-cluster structure may result in deviations in the multiplicity distributions of nuclear fragments with charge $Z=2$, compared to those predicted by the partitioning methods. Furthermore, in the framework of Tsallis statistics, the nonextensive generalized temperature, entropy index, and $q$-entropy are obtained from the multiplicity distribution of nuclear fragments with given charge number. Our work shows that fragmentation of nuclear remnants in electron-nucleus collisions at high energy is a nonextensive process.

   ↳ nucl-thnucl-exEntropy(2026)·0 citations
7. 07*

   Simultaneous Estimation of Elliptic Flow Coefficient and Impact Parameter in Heavy-Ion Collisions using CNN

   Praveen Murali🇮🇳 · Sadhana Dash🇮🇳 · Basanta Kumar Nandi🇮🇳

   A deep learning based method with Convolutional Neural Network (CNN) algorithm is developed for simultaneous determination of the Elliptic Flow coefficient ($v_2$) and the Impact Parameter in Heavy-Ion Collisions at relativistic energies. The proposed CNN is trained on Pb$-$Pb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV with minimum biased events simulated with the AMPT event generator. A total of twelve models were built on different input and output combinations and their performances were evaluated. The predictions of the CNN models were compared to the estimations of the simulated and experimental data. The deep learning model seems to preserve the centrality and $p_T$ dependence of $v_2$ at the LHC energy together with predicting successfully the impact parameter with low margins of error. This is the first time a CNN is built to predict both $v_2$ and the impact parameter simultaneously in heavy-ion system.

   ↳ hep-phnucl-exnucl-th1 citation
8. 08*

   Quadrupole-hexadecapole correlations in neutron-rich samarium and gadolinium isotopes

   L. Lotina · K. Nomura🇯🇵 · R. Rodríguez-Guzmán🇰🇿 · L.M. Robledo🇪🇸

   We present an extensive study of quadrupole-hexadecapole correlation effects in even-even Sm and Gd isotopes with neutron number $N=88-106$. The calculations are performed in the framework of the Gogny energy density functional (EDF) with the D1S parametrization and the $sdg$ interacting boson model (IBM). The quadrupole-hexadecapole constrained self-consistent mean-field potential energy surface is mapped onto the expectation value of the $sdg$-boson Hamiltonian. This procedure determines the parameters of the $sdg$-IBM Hamiltonian microscopically. Calculated excitation energies and transition strengths are compared to the ones obtained with a simpler $sd$-IBM, as well as with the experimental data. The Gogny-EDF mapped $sdg$-IBM reproduces spectroscopic properties of the studied nuclei as reasonably as in the case of the previous $sdg$-boson mapping calculations that were based on the relativistic EDF, indicating that the axial quadrupole-hexadecapole method is sound regardless of whether relativistic or nonrelativistic EDF is employed. The mapped $sdg$-IBM improves some of the results in lighter Sm and Gd isotopes compared to the mapped $sd$-IBM, implying the existence of significant hexadecapole correlations in those nuclei. For those nuclei with $N\ge 94$, hexadecapole effects are minor, and the only significant difference between the two boson models can be found in the description of $E0$ monopole transitions.

   ↳ nucl-thnucl-exPRC(2025)·7 citations
9. 09*

   Prospective report of the French QCD community to the ESPPU 2025 with respect to the program of the LHC Run 5 and beyond and future colliders at CERN

   Carolina Arata🇫🇷 · François Arleo🇫🇷 · Benjamin Audurier🇫🇷 · Alberto Baldisseri🇫🇷 · Nicole Bastid🇫🇷 · Guillaume Batigne🇫🇷 · Iouri Belikov🇫🇷 · Marcus Bluhm🇫🇷 · Francesco Bossu🇫🇷 · Hervé Borel🇫🇷 · Renaud Boussarie🇫🇷 · Javier Castillo Castellanos🇫🇷 and 50 other authors

   This document summarizes the prospective physics plans of the French QCD and Heavy-Ion community, including the experimental programs at the LHC Run 5 and beyond and future colliders at CERN, within the context of the French contribution to the update of the European Strategy in Particle Physics (ESPPU 2025), as discussed in the workshop on European Strategy for Particle Physics Update 2025 organised by the QCD GdR in Oct. 2024.

   ↳ hep-phhep-exnucl-exnucl-th0 citations
10. 10*

    $\Lambda NN$ input to neutron stars from hypernuclear data

    Eliahu Friedman🇮🇱 · Avraham Gal🇮🇱

    This work is a sequel to our two 2023 publications [PLB 837 137669, NPA 1039 122725] where fitting 14 1$s_{\Lambda }$ and 1$p_{\Lambda }$ single-particle binding energies in hypernuclei across the periodic table led to a well-defined $\Lambda$-nucleus optical potential. The potential consists of a Pauli modified linear-density ($\Lambda N$) and a quadratic-density ($\Lambda NN$) terms. The present work reports on extending the above analysis to 21 $\Lambda$ single-particle data points input by including 1$d_{\Lambda }$ and 1$f_{\Lambda }$ states in medium-weight and heavy hypernuclei. The upgraded results for the $\Lambda N$ and $\Lambda NN$ potential depths at nuclear-matter density ${\rho }_0=0.17$~fm${}^{-3}$, $D_{\Lambda }^{(2)}=-37.5\mp 0.7$~MeV and $D_{\Lambda }^{(3)}=+9.8\pm 1.2$~MeV together with the total depth $D_{\Lambda }=-27.7\pm 0.5$~MeV, agree within errors with the earlier results. The $\Lambda$ hypernuclear overbinding associated with the $\Lambda N$-induced potential depth $D_{\Lambda }^{(2)}$ agrees quantitatively with a recent combined analysis of low-energy $\Lambda p$ scattering data and correlation functions [PLB 850 (2024) 138550]. These results, particularly the size of the repulsive $D_{\Lambda }^{(3)}$, provide an essential input towards resolving the 'hyperon puzzle' in the core of neutron stars. We also show that a key property of our $\Lambda NN$-induced potential term, i.e. a need to suppress the quadratic-density $\Lambda NN$ term involving an excess neutron and a $N=Z$ core nucleon, can be tested in the forthcoming JLab E12-15-008 experiment.

    ↳ nucl-thnucl-exPoS(2025)·5 citations
11. 11*

    An introduction to relativistic spin hydrodynamics

    Xu-Guang Huang🇨🇳

    Spin polarization and spin transport are common phenomena in many quantum systems. Relativistic spin hydrodynamics provides an effective low-energy framework to describe these processes in quantum many-body systems. The fundamental symmetry underlying relativistic spin hydrodynamics is angular momentum conservation, which naturally leads to inter-conversion between spin and orbital angular momenta. This inter-conversion is a key feature of relativistic spin hydrodynamics, closely related to entropy production and introducing ambiguity in the construction of constitutive relations. In this article, we present a pedagogical introduction to relativistic spin hydrodynamics. We demonstrate how to derive the constitutive relations by applying local thermodynamic laws and explore several distinctive aspects of spin hydrodynamics. These include the pseudo-gauge ambiguity, the behavior of the system in the presence of strong vorticity, and the challenges of modeling the freeze-out of spin in heavy-ion collisions. We also outline some future prospects for spin hydrodynamics.

    ↳ nucl-thhep-phnucl-exphysics.flu-dynNucl.Sci.Tech.(2025)·35 citations
12. 12*

    Energy-Energy Correlator for jet production in $pp$ and $pA$ collisions

    João Barata🇨🇭 · Zhong-Bo Kang🇺🇸 · Xoán Mayo López🇪🇸 · Jani Penttala🇺🇸

    In this Letter, we study the collinear limit of the Energy-Energy Correlator (EEC) in single-inclusive jet production in proton-proton ($pp$) and proton-nucleus ($pA$) collisions. We introduce a non-perturbative model that allows us to describe the EEC in the entire angular region of the current experiments. Our results for $pp$ collisions show excellent agreement with CMS and ALICE data over a wide range of jet transverse momenta. For $pA$ collisions, we include modifications from the nuclear medium, and our predictions align well with the trends observed in recent ALICE measurements.

    ↳ hep-phhep-exnucl-exnucl-thPRL(2025)·43 citations
13. 13*

    Novel Application of Neutrinos to Evaluate U.S. Nuclear Weapons Performance

    J.R. Distel · E.C. Dunton🇺🇸 · J.M. Durham🇺🇸 · A.C. Hayes🇨🇦 · W.C. Louis🇺🇸 · J.D. Martin🇺🇸 · G.W. Misch · M.R. Mumpower🇺🇸 · Z. Tang🇺🇸 · R.T. Thornton🇺🇸 · B.T. Turner · R.G. Van de Water🇺🇸 · W.S. Wilburn

    There is a growing realization that neutrinos can be used as a diagnostic tool to better understand the inner workings of a nuclear weapon. Robust estimates demonstrate that an Inverse Beta Decay (IBD) neutrino scintillation detector built at the Nevada Test Site of 1000-ton active target mass at a standoff distance of 500 m would detect thousands of neutrino events per kTe of nuclear yield. This would provide less than 4% statistical error on measured neutrino rate and 5% error on neutrino energy. Extrapolating this to an error on the test device explosive yield requires knowledge from evaluated nuclear databases, non-equilibrium fission rates, and assumptions on internal neutron fluxes. Initial calculations demonstrate that prompt neutrino rates from a short pulse of Pu-239 fission is about a factor of two less than that from a steady state assumption. As well, there are significant energy spectral differences as a function of time after the pulse that needs to be considered. In the absence of nuclear weapons testing, many of the technical and theoretical challenges of a full nuclear test could be mitigated with a low cost smaller scale 20 ton fiducial mass IBD demonstration detector placed near a TRIGA pulsed reactor. The short duty cycle and repeatability of pulses would provide critical real environment testing and the measured neutrino rate as a function of time data would provide unique constraints on fission databases and equilibrium assumptions.

    ↳ physics.ins-dethep-exnucl-exRev.Sci.Instrum.(2025)·2 citations
14. 14*

    Variable Rate Neural Compression for Sparse Detector Data

    Yi Huang🇺🇸 · Yeonju Go🇺🇸 · Jin Huang🇺🇸 · Shuhang Li🇺🇸 · Xihaier Luo🇺🇸 · Thomas Marshall🇺🇸 · Joseph Osborn🇺🇸 · Christopher Pinkenburg🇺🇸 · Yihui Ren🇺🇸 · Evgeny Shulga🇺🇸 · Shinjae Yoo🇺🇸 · Byung-Jun Yoon🇺🇸

    High-energy large-scale particle colliders generate data at extraordinary rates. Developing real-time high-throughput data compression algorithms to reduce data volume and meet the bandwidth requirement for storage has become increasingly critical. Deep learning is a promising technology that can address this challenging topic. At the newly constructed sPHENIX experiment at the Relativistic Heavy Ion Collider, a Time Projection Chamber (TPC) serves as the main tracking detector, which records three-dimensional particle trajectories in a volume of a gas-filled cylinder. In terms of occupancy, the resulting data flow can be very sparse reaching $10^{-3}$ for proton-proton collisions. Such sparsity presents a challenge to conventional learning-free lossy compression algorithms, such as SZ, ZFP, and MGARD. In contrast, emerging deep learning-based models, particularly those utilizing convolutional neural networks for compression, have outperformed these conventional methods in terms of compression ratios and reconstruction accuracy. However, research on the efficacy of these deep learning models in handling sparse datasets, like those produced in particle colliders, remains limited. Furthermore, most deep learning models do not adapt their processing speeds to data sparsity, which affects efficiency. To address this issue, we propose a novel approach for TPC data compression via key-point identification facilitated by sparse convolution. Our proposed algorithm, BCAE-VS, achieves a $75\%$ improvement in reconstruction accuracy with a $10\%$ increase in compression ratio over the previous state-of-the-art model. Additionally, BCAE-VS manages to achieve these results with a model size over two orders of magnitude smaller. Lastly, we have experimentally verified that as sparsity increases, so does the model's throughput.

    ↳ physics.ins-detcs.AIhep-exnucl-ex1 citation
15. 15*

    Neutron Counting Statistics calculations Using Deterministic Transport

    Philippe Humbert🇫🇷

    For a number of applications like low-source reactor start-up or neutron coincidence counting it is necessary to take into account the stochastic nature of neutron transport and go beyond the average neutron density, which is solution of a linear Boltzmann equation. In this work, we are particularly interested in calculating the moments and probabilities of the number of neutrons detected during a time window. It is known that in case of a single initial neutron these quantities are solution of a system of coupled adjoint transport equations and that a neutron source can be taken into account in a second time using summations with the source strength. The purpose of the present work is first to present the derivation of these equations in a form where they can be solved up an arbitrary order and where the fission terms are expanded according to the moments of the fission multiplicity. For simplicity, the derivation is first presented in a lumped also called point model approximation before considering the full phase-space case. Thereafter, we describe the implementation of the solution algorithm in the deterministic, discrete ordinates code PANDA and finally, we present some numerical results and inter-code comparisons for verification purposes and to illustrate the applicability of the method.

    ↳ physics.comp-phnucl-exNucl.Sci.Eng.(2026)·0 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.