PaperPanorama

Nuclear Experiment·nucl-ex

Thu·Apr 3, 2025

8 papers3 primary·5 cross-listed·reconstructed*

  1. 01*

    Binding energy of and via image analyses of nuclear emulsions using deep-learning

    Ayumi Kasagi🇯🇵 · Takehiko R. Saito🇯🇵 · Vasyl Drozd🇯🇵 · Hiroyuki Ekawa🇯🇵 · Samuel Escrig🇯🇵 · Yiming Gao🇯🇵 · Yan He🇯🇵 · Enqiang Liu🇯🇵 · Abdul Muneem🇯🇵 · Manami Nakagawa🇯🇵 · Kazuma Nakazawa🇯🇵 · Christophe Rappold🇪🇸 and 7 other authors

    Subatomic systems are pivotal for understanding fundamental baryonic interactions, as they provide direct access to quark-level degrees of freedom. In particular, introducing a strange quark adds "strangeness" as a new dimension, offering a powerful tool for exploring nuclear forces. The hypertriton, the lightest three-body hypernuclear system, provides an ideal testing ground for investigating baryonic interactions and quark behavior involving up, down, and strange quarks. However, experimental measurements of its lifetime and binding energy, key indicators of baryonic interactions, show significant deviations in results obtained from energetic collisions of heavy-ion beams. Identifying alternative pathways for precisely measuring the hypertriton's binding energy and lifetime is thus crucial for advancing experimental and theoretical nuclear physics. Here, we present an experimental study on the binding energies of (hypertriton) and , performed through the analysis of photographic nuclear emulsions using modern techniques. By incorporating deep-learning methods, we uncovered systematic uncertainties in conventional nuclear emulsion analyses and established a refined calibration protocol for determining binding energies accurately. Our results are independent of those obtained from heavy-ion collision experiments, offering a complementary measurement and opening new avenues for investigating few-body hypernuclei interactions.

    nucl-exPTEP(2025)·10 citations
  2. 02*

    Single-atom-at-a-time adsorption studies of Bi and its precursor Pb on SiO surfaces

    Dominik Dietzel · Alexander Yakushev · Christoph E. Düllmann🇩🇪 · Jadambaa Khuyagbaatar · Jörg Krier · Egon Jäger

    In preparation of gas-phase chemical experiments with moscovium (Mc, element 115), we studied the chemical behavior of the short-lived bismuth radioisotope Bi in helium, argon, and oxygen atmosphere. Internal chromatograms were recorded as a function of various parameters including carrier gas type and flow rate, thus characterizing the novel miniCOMPACT detector array. This aids to optimize the conditions for experiments with superheavy elements. The bismuth progeny of Rn deposited on the SiO surface of the miniCOMPACT via diffusion-controlled deposition. Bismuth showed the expected high reactivity towards the SiO surface of the miniCOMPACT. Experiments in argon and oxygen atmosphere showed no measurable differences in the deposition distribution of the activity. The intermediate 36-min Pb is a member of the Ac decay chain, feeding the studied bismuth isotope, was taken into account. To extract thermodynamical data from the results, namely the lower limit of the value of the adsorption enthalpy of Bi on SiO, we performed Monte Carlo simulations, adapted to account for the precursor effect, and compared the experimental results to their output. Simulations were also performed for bismuths heavier homologue, moscovium, using a theoretically predicted value for the adsorption enthalpy of this element on SiO. These suggest moscovium to adsorb in the first part of the miniCOMPACT detection array, in line with recent observations.

    nucl-exphysics.ins-detRadiochimica Acta, Volume 113, Number 3, …·1 citation
  3. 03*

    Onset of Constituent Quark Number Scaling in Heavy-Ion Collisions at RHIC

    STAR Collaboration: B. E. Aboona · J. Adam · L. Adamczyk · I. Aggarwal · M. M. Aggarwal · Z. Ahammed · A. K. Alshammri · E. C. Aschenauer · S. Aslam · J. Atchison · V. Bairathi · X. Bao and 359 other authors

    Partonic collectivity is one of the necessary signatures for the formation of quark-gluon plasma in high-energy nuclear collisions. Number of constituent quarks (NCQ) scaling has been observed for hadron elliptic flow in top energy nuclear collisions at the Relativistic Heavy Ion Collider and the LHC, and this has been theoretically suggested as strong evidence for partonic collectivity. In this Letter, a systematic analysis of of , , , , and in Au+Au collisions at = 3.2, 3.5, 3.9, and 4.5 GeV, with the STAR experiment at the Relativistic Heavy Ion Collider, is presented. NCQ scaling is markedly violated at 3.2 GeV, consistent with a hadronic-interaction dominated equation of state. However, as the collision energy increases, a gradual evolution to NCQ scaling is observed. This beam-energy dependence of for all hadrons studied provides evidence for the onset of dominant partonic interactions by = 4.5 GeV.

    nucl-exhep-exPRL(2025)·22 citations
  4. 04*

    Towards the determination of CP-odd pion-nucleon couplings

    Shohini Bhattacharya🇺🇸 · Kaori Fuyuto🇺🇸 · Emanuele Mereghetti🇺🇸 · Thomas R. Richardson🇺🇸

    The nucleon matrix elements (NMEs) associated with quark chromo-magnetic dipole moments (cMDMs) play a crucial role in determining the CP-odd pion-nucleon couplings induced by quark chromo-electric dipole moments. In recent years, it has been argued that the NMEs of cMDMs can be related to the third moment of the nucleon's higher-twist (specifically, twist-three) parton distribution function (PDF) , which can, in principle, be measured through dihadron production in semi-inclusive deep inelastic scattering processes. By applying the spin-flavor expansion to the cMDM operators in the large- limit, where is the number of quark colors, we show that the NMEs receive contributions not only from the twist-three PDF but also from an additional, previously neglected nucleon form factor. Incorporating constraints from the spin-flavor expansion, recent experimental data on , as well as model calculations of , we estimate the NMEs of the cMDM operators. Our analysis indicates that the NMEs are dominated by the nucleon form factors, and the cMDM contributions to pion-nucleon couplings can be comparable to those from the quark sigma terms.

    hep-phhep-latnucl-exnucl-thPRC(2025)·4 citations
  5. 05*

    Measurement of Spin-Density Matrix Elements in Photoproduction with a Linearly Polarized Photon Beam at GeV

    GlueX Collaboration

    We measure the spin-density matrix elements (SDMEs) for the photoproduction of off of the proton in its decay to , using 105 pb of data collected with a linearly polarized photon beam using the GlueX experiment. The SDMEs are measured in nine bins of the squared four-momentum transfer in the range GeV, providing the first measurement of their -dependence for photon beam energies GeV. We confirm the dominance of Pomeron exchange in this region, and put constraints on the contribution of other Regge exchanges. We also find that helicity amplitudes where the helicity of the photon and the differ by two units are negligible.

    hep-exnucl-exPRC(2025)·2 citations
  6. 06*

    Proton cumulants from hydrodynamics in light of new STAR data

    Volodymyr Vovchenko🇺🇸 · Volker Koch🇺🇸

    New measurements of proton number cumulants from the Beam Energy Scan Phase II (BES-II) program at RHIC by the STAR Collaboration provide unprecedented precision and insights into the properties of strongly interacting matter. This report discusses the measurements in the context of predictions from hydrodynamics, emphasizing the enhanced sensitivity of factorial cumulants and their implications for the search for the QCD critical point. The experimental data shows enhancement of second-order factorial cumulants and suppression of third-order factorial cumulants relative to the non-critical baseline at GeV. We discuss implications of this observation for the possible location of the critical point in the QCD phase diagram and opportunities for future measurements of acceptance dependence of factorial cumulants.

    nucl-thhep-phnucl-exJ.Subatomic Part.Cosmol.(2025)·5 citations
  7. 07*

    A simple schematic model for a cross section deficit in C+C fusion reactions

    K. Hagino

    A cross section deficit phenomenon has been observed in C+C fusion reactions at astrophysical energies, at which fusion cross sections are suppressed in the off-resonance regions as compared to fusion cross sections for the C+C system. I here construct a simple schematic model which simulates this phenomenon. The model consists of a random matrix Hamiltonian based on the Gaussian Orthogonal Ensemble (GOE), which is coupled to an entrance channel Hamiltonian in the discrete basis representation. I show that the transmission coefficients are almost unity when both the level density and the decay widths of the GOE configurations are large, realizing the strong absorption regime. On the other hand, when these parameters are small, the transmission coefficients are significantly structured as a function of energy. In that situation, the transmission coefficients at resonance energies reach unity in this model, that is consistent with the experimental finding of the cross section deficit.

    nucl-thnucl-ex0 citations
  8. 08*

    US National Input to the European Strategy Update for Particle Physics

    André de Gouvêa🇺🇸 · Hitoshi Murayama🇺🇸 · Mark Palmer🇺🇸 · Heidi Schellman🇺🇸

    In this document we summarize the output of the US community planning exercises for particle physics that were performed between 2020 and 2023 and comment upon progress made since then towards our common scientific goals. This document leans heavily on the formal report of the Particle Physics Project Prioritization Panel and other recent US planning documents, often quoting them verbatim to retain the community consensus.

    hep-exnucl-ex1 citation

* 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.