Tue·Aug 19, 2025Tuesday·August 19, 2025

1. 01*

   Observation of Tensor-Driven High-Momentum Neutrons in ${}^{16}$O via ($p,d$) Reactions and Zero-Degree Deuteron Momentum Spectroscopy

   X. Wang · H. J. Ong · S. Terashima · I. Tanihata · Y. K. Tanaka · N. Aoi · Y. Ayyad · J. Benlliure · F. Farinon · H. Fujioka · H. Geissel · J. Gellanki and 33 other authors

   The ${}^{16}\mathrm{O}(p,d{)}^{15}\mathrm{O}$ reaction has been studied at $0^{\circ }$ using 403-, 604-, 907- and 1209-MeV protons, comparing cross sections populating positive- and negative-parity states in ${}^{15}\mathrm{O}$. Transitions to positive-parity states exhibit strong sensitivity to high-momentum neutrons, while negative-parity transitions show much smaller effects. The cross-section ratio between positive- and negative-parity states rises sharply with momentum transfer, matching theoretical predictions that include tensor interactions, particularly the peak near $2{\mathrm{fm}}^{-1}$ for the $5/2^{+}$ to ground-state ratio. These results highlight $0^{\circ }$ neutron-pickup reactions as a sensitive probe for tensor-driven high-momentum components, paving the way for studies in exotic nuclei via radioactive beams.

   nucl-exPLB(2026)·1 citation
2. 02*

   Cross talk between experimental data and simple validation of shell closure in pre-actinides

   Punit Dubey · Mahima Upadhyay · Mahesh Choudhary · Namrata Singh · Sriya Paul · Shweta Singh🇩🇪 · N. Saneesh · Mohit Kumar · Rishabh Prajapati · K. S. Golda · Akhil Jhingan🇮🇳 · P. Sugathan and 4 other authors

   Two back-to-back experiments, 28Si + 178Hf and 28Si + 186W, were intentionally conducted to validate the role of shell closure in pre-actinides by studying neutron multiplicity in compound nucleus (CN) 206Rn and 214Ra. In the first experiment, Dubey et al. [Phys. Rev. C 112, L011602 (2025)], we established the influence of the neutron shell closure. In the present work, the CN 214Ra was deliberately selected to investigate the dependence of the total neutron multiplicity (Mtotal) on the proton number (Z), while keeping the neutron number constant at N = 126 in the pre-actinide region. The objective of the study is two-fold : (i) to examine the effect of proton shell closure when moving away from Z = 82, and (ii) to correlate the present results on proton shell closure with our previous finding on neutron shell closure. We have also used the previous reported data for N = 126 isotones 210Po, 212Rn, and 213Fr to establish the validation of shell closure. A systematic increase in Mtotal with increasing Z was observed from Z = 82 to Z = 88. Furthermore, comparison of the present results on proton shell closure with our earlier neutron shell closure observation, reveals that the cross-correlation between neutron and proton shell closure shows a systematic increase in Mtotal as one moves away from 208Pb, whether along isotonic or isotopic chains.

   nucl-ex0 citations
3. 03*

   IsoDAR@Yemilab: Preliminary Design Report -- Volume II: Medium Energy Beam Transport, Neutrino Source, and Shielding

   Joshua Spitz🇺🇸 · Jose R. Alonso🇺🇸 · Jon Ameel🇺🇸 · Roger Barlow🇬🇧 · Larry Bartoszek🇺🇸 · Adriana Bungau🇺🇸 · Michael H. Shaevitz🇺🇸 · Erik A. Voirin🇺🇸 · Daniel Winklehner🇺🇸 · Janet M. Conrad🇺🇸 · Samuel J. Engebretson🇺🇸 · Jarrett Moon🇺🇸 and 10 other authors

   This Preliminary Design Report (PDR) describes the IsoDAR electron-antineutrino source in two volumes which are mostly site-independent and describe the cyclotron driver providing a 60 MeV, 10 mA proton beam (Volume I); and the medium energy beam transport line (MEBT) and target (this Volume). The IsoDAR driver and target will produce about $1.15\cdot 10^{23}$ electron-antineutrinos over five calendar years. Paired with a kton-scale liquid scintillator detector, this will enable a broad particle physics program including searches for new symmetries, new interactions and new particles. Here in Volume II, we describe the medium energy beam transport line, the antineutrino source beam-target and surrounding sleeve, shielding, and plans for monitoring and installation.

   ↳ hep-exnucl-exphysics.ins-det1 citation
4. 04*

   In-medium heavy quark-antiquark $T$-matrix without partial wave expansion

   Anurag Tiwari🇨🇳 · Min He🇨🇳

   The T-matrix of the heavy quark-antiquark ($Q\bar{Q}$) pair interacting through a screened Cornell potential in the quark-gluon plasma (QGP) is computed without employing the partial wave expansion. This is compared with the results obtained using the conventional method of partial wave expansion. Through a comprehensive survey over a range of screening mass and center-of-mass energy, which, when combined, determine the orbital angular momentum involved in the scattering through the associated force range and incident momentum, it is demonstrated that a substantial number of partial wave terms are necessary to precisely match the full scattering amplitude directly obtained from the method without partial wave expansion. For moderate screening masses (corresponding to one to two times the crossover transition temperature) and center-of-mass energy, the number of partial waves required for satisfactory matching turns out as large as 10-20, substantially larger than what one would expect based on simply measuring the magnitudes of the first few partial wave amplitudes. This highlights the efficiency of the new method in directly obtaining the full scattering amplitude needed for further computation of phenomenological observables. We also employ the new method to calculate the T-matrix at center-of-mass energies below the $Q\bar{Q}$ mass threshold, and demonstrate the presence of bound states of different orbital quantum numbers simultaneously in a single energy scan.

   ↳ hep-phnucl-exnucl-thPRC(2026)·1 citation
5. 05*

   Simulation of heavy quarkonium equilibration in the quark-gluon plasma

   Shouxing Zhao🇨🇳 · Min He🇨🇳

   We simulate the heavy quarkonium equilibration through transport in a static and homogeneous quark-gluon plasma (QGP) box within the semi-classical Boltzmann approach incorporating both the leading-order and next-to-leading-order dissociation and regeneration reactions. The scattering amplitudes involved are taken from perturbative computations based on effective color-electric dipole coupling of the heavy quarkonium with thermal gluons. By coupling the Langevin simulation of single heavy quark diffusion and the Boltzmann transport of the heavy quarkonium in a real-time fashion, we demonstrate how the kinetic and chemical equilibrium of heavy quarkonium with single heavy quarks in the medium is achieved in terms of both the bound state's yields and momentum distributions. The pertinent equilibration time turns out to be comparable to the lifetime of the QGP created in the most central heavy-ion collisions at the LHC energies. The role of the intricate interplay between the open and hidden heavy sector in the process of equilibration is highlighted. This work provides a dynamical way of understanding the phenomenological success of statistical hadronization model for charmonium production in relativistic heavy-ion collisions, and also paves the way for realistic phenomenological applications to heavy quarkonium transport.

   ↳ hep-phnucl-exnucl-thPRD(2025)·1 citation
6. 06*

   Annihilation Vertex Reconstruction Algorithm with Single-Layer Timepix4 Detectors

   Viktoria Kraxberger🇦🇹 · Angela Gligorova🇦🇹 · Eberhard Widmann🇦🇹

   A study of antiproton-nucleus annihilations at rest on a variety of thin solid targets using slow extracted antiprotons is being prepared. To detect the charged annihilation products, the experiment will employ seven Timepix4 ASICs coupled to 500 um thick silicon sensors. These will be arranged in a cuboid geometry that covers the majority of the full solid angle around the target, enabling precise tracking of outgoing particles using only one layer of detectors. With these novel chips, the annihilation will be studied by measuring the total multiplicity, energy, and angular distribution of various prongs produced in a number of targets. A 3D reconstruction algorithm for determining the annihilation vertex from particle tracks in the single-plane detectors has been developed using Monte Carlo simulations. This allows for event-by-event reconstruction, making it possible to distinguish antiproton annihilations on the target from those occurring elsewhere. The measurements will also enable a study of possible final state interactions triggered by the primary annihilation mesons, their evolution with the nuclear mass and their branching ratios.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2026)·0 citations
7. 07*

   Influence of Cluster Configurations and Nucleon--Nucleon Scattering Cross-Section on Stopping Power in Heavy-Ion Collisions

   S. Y. Yao🇨🇳 · X. G. Deng🇨🇳 · Y. G. Ma🇨🇳

   We investigate the impacts of nuclear $\alpha$-clustering structures and nucleon--nucleon cross-section on nuclear stopping power for ${}^{16}\text{O}$ + ${}^{40}\text{Ca}$ collisions below 300 MeV/nucleon using an extended quantum molecular dynamics (EQMD) model. Our results show that the specific $\alpha$-clustering configurations of ${}^{16}\text{O}$--including chain, square, kite, and tetrahedron--have a significant effect on collision dynamics. Among them, the tightly bound tetrahedral structure exhibits the highest stopping power. Moreover, the repulsive Coulomb interaction is found to reduce the stopping power of protons in the Fermi-energy domain. At higher energies, the decreasing trend is influenced by both the nucleon--nucleon cross-section and the mean field.

   ↳ nucl-thnucl-exPRC(2025)·2 citations
8. 08*

   Relativistic atomic structure calculations in support of spectroscopy

   L. F. Pašteka🇳🇱 · E. Eliav🇮🇱 · M. L. Reitsma🇳🇱 · A. Borschevsky🇳🇱

   Theory can provide important support at all the stages of spectroscopic experiments, from planning the measurements to the interpretation of the results. Such support is particularly valuable for the challenging experiments on heavy, unstable, and superheavy elements and for precision measurements aimed at testing the Standard Model of particle physics. To be reliable and useful in experimental context, theoretical predictions should be based on high-accuracy calculations. For heavy elements, such calculations must treat both relativistic effects and electron correlation on the highest possible level. Relativistic coupled cluster is considered one of the most powerful methods for accurate calculations on heavy many-electron atoms and molecules. This approach is highly accurate and versatile and can be used to obtain energies and a variety of atomic and molecular properties. Furthermore, its robust and transparent formulation allows for systematic improvement of the accuracy of the calculated results and for assigning uncertainties on theoretical values. The Fock-space coupled cluster (FSCC) variant of this method is particularly useful in the context of spectroscopic measurements as it provides access to atomic spectra and properties of the excited states. In this review, we present in detail the relativistic coupled cluster approach and its FSCC variant. We provide a description of the computational procedure used for accurate calculations and for assigning uncertainties. Outstanding recent examples of application to atomic properties, focusing on the experimental context are presented. Finally, we provide a brief discussion of the perspectives for future developments and applications of the CC approach.

   ↳ physics.atom-phnucl-exphysics.chem-phPPNP(2026)·1 citation
9. 09*

   Reaction processes of muon-catalyzed fusion in the muonic molecule $dd\mu$ studied with the tractable $T$-matrix model

   Qian Wu🇨🇳 · Zhu-Fang Cui🇨🇳 · Masayasu Kamimura

   Muon-catalyzed fusion has recently regained significant attention due to experimental and theoretical developments being performed. The present authors [Phys. Rev. C {\bf 109} 054625 (2024)] proposed the tractable $T$-matrix model based on the Lippmann-Schwinger equation to approximate the elaborate two- and three-body coupled-channel (CC) calculations [Kamimura, Kino, and Yamashita, Phys. Rev. C {\bf 107}, 034607 (2023)] for the nuclear reaction processes in the muonic molecule $dt\mu$, $(dt\mu {)}_{J=0}\to {}^4\mathrm{He}+n+\mu +17.6\mathrm{MeV}$. % or ${(}^4\mathrm{He}\mu {)}_{nl}+n+17.6\mathrm{MeV}$. The $T$-matrix model well reproduced almost all of the results generated by the CC work. In the present paper, we apply this model to the nuclear reaction processes in the $dd\mu$ molecule, $(dd\mu {)}_{J=1}\to {}^3\mathrm{He}+n+\mu +3.27$ MeV or $t+p+\mu +4.03$ MeV, in which the fusion takes place via the $p$-wave $d$-$d$ relative motion. Recently, significantly different $p$-wave astrophysical $S(E)$ factors of the reaction $d+d\to {}^3\mathrm{He}+n$ or $t+p$ at $E\simeq 1$ keV to 1 MeV have been reported experimentally and theoretically by five groups. Employing many sets of nuclear interactions that can reproduce those five cases of $p$-wave $S(E)$ factors, we calculate the fusion rate of the $(dd\mu {)}_{J=1}$ molecule using three kinds of methods where results are consistent with each other. We also derive the ${}^3\mathrm{He}$-$\mu$ sticking probability and the absolute values of the energy and momentum spectra of the emitted muon. The violation of charge symmetry in the $p$-wave $d$-$d$ reaction and the $dd\mu$ fusion reaction is discussed. Information on the emitted 2.45-MeV neutrons and \mbox{1 keV-dominant} muons should be useful for the application of $dd\mu$ fusion.

   ↳ nucl-thnucl-exphysics.atom-phPRC(2026)·4 citations
10. 10*

    Transfer Learning for Neutrino Scattering: Domain Adaptation with GANs

    Jose L. Bonilla🇵🇱 · Krzysztof M. Graczyk🇵🇱 · Artur M. Ankowski🇵🇱 · Rwik Dharmapal Banerjee🇵🇱 · Beata E. Kowal🇵🇱 · Hemant Prasad🇵🇱 · Jan T. Sobczyk🇵🇱

    Transfer learning (TL) is used to extrapolate the physics information encoded in a Generative Adversarial Network (GAN) trained on synthetic neutrino-carbon inclusive scattering data to related processes such as neutrino-argon and antineutrino-carbon interactions. We investigate how much of the underlying lepton-nucleus dynamics is shared across different targets and processes. We also assess the effectiveness of TL when training data is obtained from a different neutrino-nucleus interaction model. Our results show that TL not only reproduces key features of lepton kinematics, including the quasielastic and $\Delta$-resonance peaks, but also significantly outperforms generative models trained from scratch. Using data sets of 10,000 and 100,000 events, we find that TL maintains high accuracy even with limited statistics. Our findings demonstrate that TL provides a well-motivated and efficient framework for modeling (anti)neutrino-nucleus interactions and for constructing next-generation neutrino-scattering event generators, particularly valuable when experimental data are sparse.

    ↳ hep-phcs.LGhep-exnucl-ex+1PRD(2026)·4 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.