PaperPanorama

Nuclear Experiment·nucl-ex

Wed·Sep 23, 2026

9 papers—3 primary·6 cross-listed

All9Primary3Cross-lists6
  1. 01

    Observation of a magnetic shift in neutron whispering-gallery states

    K. Schreiner · J. A. Pioquinto · S. Baeßler · V. V. Nesvizhevsky · P. Clade · P. Crivelli · R. Cubitt · J. Guyomard · C. Killian · U. Miniotaite · F. Nez · E. Perry and 10 other authors

    We developed experimental and theoretical methods to create and describe high-resolution whispering-gallery interference patterns and show the feasibility of measuring their small shifts by external interactions. Such experiments can be used to search for extra fundamental interactions, time parity violations, nonzero electric charges, precisely measuring the gravitational properties of (anti)matter, parity violations, neutron polarizability, quantum reflection, surface state effects, etc. Here, we measure a magnetic shift of such a neutron pattern , and our sensitivity to spin-dependent differences between the scattering lengths was .

    nucl-ex
  2. 02

    Photoneutron reactions on Ho and Tm in the giant dipole resonance region

    I. Gheorghe · S. Goriely · K. Stopani · S. Belyshev · M. Krzysiek · D. Filipescu · H. Wang · G. Fan · L. Liu · H. Scheit · D. Symochko · T. Aumann and 10 other authors

    Photoneutron reactions were investigated for the deformed Ho and Tm nuclei from the vicinity of the neutron emission threshold up to 40~MeV, well above the giant dipole resonance (GDR) region, using quasimonochromatic laser Compton scattering -ray beams provided at the NewSUBARU facility, Japan. A high-and-flat efficiency moderated array of He counters was used for the neutron detection and an associated neutron multiplicity sorting method for extracting the , , and reaction cross sections and average neutron emission energies. The present Ho cross sections were compared to existing data, revealing discrepancies with the Saclay multiplicity sorting results and an overall 10 strength difference with the Livermore ones. There are no other data for Tm. GDR parameters based on phenomenological Lorentzian models were extracted by fitting the present data with adjustments for the missing contribution of charged-particle-only reactions not observed experimentally. For both nuclei we observed high energy structures at 20-25~MeV, matching giant quadrupole resonance KMFR predictions. Based on the present centroid energies of the first and second GDR peaks, hydrodynamic model predictions gave intrinsic electric quadrupole moments of +7.00(34)~b and +7.38(28)~b for the ground states of Ho and Tm, respectively. The present experimental excitation functions and photoneutron energies were compared to statistical model calculations. Using the EMPIRE code, we performed a sensitivity test to phenomenological models of photon strength functions and nuclear level densities. The TALYS code was used to reproduce the present experimental cross sections and average neutron energies using microscopic nuclear level density models.

    nucl-ex
  3. 03

    Non-Monotonicity of Correlations in Au + Au Collisions at RHIC

    Rutik Manikandhan

    We report the first measurements of two-particle transverse momentum correlations for mid-rapidity charged particles in Au+Au collisions at 3.0, 3.2, 3.5, 3.9, 4.5, 5.2 and 7.7 GeV recorded by the STAR experiment. The results are compared with previous STAR measurements from the Beam Energy Scan Phase I (BES-I) and with transport model calculations. The measured two-particle correlators exhibit an approximate power-law scaling with the number of participating nucleons (), consistent with expectations from an independent-source scenario. This scaling is least well described at the lowest collision energy, ~GeV. Furthermore, a non-monotonic energy dependence of the correlations is observed in central collisions, representing the first systematic observation of such behavior as a function of collision energy.

    nucl-exhep-exJournal of Subatomic Particles and Cosmol…
  4. 04

    Comparative Study of Color Glass Condensate and Collinear Frameworks for Large-Transverse-Momentum Semi-Inclusive Deep Inelastic Scattering

    Swagato Mukherjee · Björn Schenke · Shaswat Tiwari

    We study the Semi-Inclusive Deep Inelastic Scattering (SIDIS) cross-section at large values of hadron transverse momentum , with being the photon virtuality. This kinematic regime of SIDIS allows for a collinear factorization in terms of parton distribution functions (PDFs) and collinear fragmentation functions (FFs). On the other hand, at high energies, i.e., at small Bjorken , the same SIDIS process can also be factorized within the Color Glass Condensate (CGC) framework in terms of eikonal dipole amplitudes. In this work, we perform a systematic comparison of the leading-order (LO) and next-to-leading-order (NLO) collinear and the LO CGC factorizations of this process based on the COMPASS and HERA data. We further provide comparisons of these two factorization frameworks for nucleon and nuclear large- SIDIS in the expected Electron Ion Collider (EIC) kinematics. We find, within the present theoretical uncertainties, that it might be difficult to distinguish between these two factorization schemes for nuclear SIDIS at the EIC. We also observe a significant dependence of the LO eikonal CGC predictions on the choice of longitudinal momentum fraction , suggesting significant beyond-eikonal corrections for the EIC kinematics.

    ↳ hep-phnucl-th
  5. 05

    Gradient Flow for the Jet Transport Coefficient: A Quenched Lattice Benchmark

    Hai-Tao Shu · Cheng Zhang

    We apply the gradient-flow framework to determine the nonperturbative medium contribution to the jet transport coefficient using quenched lattice QCD in the temperature range . The calculation focuses on the leading-twist contribution at leading order for an asymptotically energetic quark propagating through a thermal pure-gluon plasma. In the infinite-energy limit, the operator-product expansion expresses in pure gauge theory as the product of a perturbative short-distance coefficient and the entropy density . The latter is determined from the gradient-flow energy-momentum tensor at three lattice spacings for each temperature and the former is estimated perturbatively at one-loop order. We find that is strongly suppressed below , rises rapidly across the deconfinement transition, and remains approximately constant at throughout the deconfined temperature range studied. This is statistically consistent with the previous quenched lattice determination based on a different renormalization procedure, providing a nontrivial validation of the gradient-flow framework for the jet transport coefficient. The systematic treatment of operator renormalization and matching provided by gradient flow becomes particularly important in full QCD, because the need to renormalize quark operators and account for their mixing with the gluonic sector can likewise be addressed within the same framework.

    ↳ hep-lathep-phnucl-exnucl-th
  6. 06

    Pulse-shape discrimination with machine learning for CZT detectors at the DANE beam test facility

    Simone Manti · Francesco Artibani · Leonardo Abbene · Massimiliano Bazzi · Manuele Bettelli · Giacomo Borghi · Damir Bosnar · Mario Bragadireanu · Antonino Buttacavoli · Mario Carminati · Alberto Clozza · Francesco Clozza and 27 other authors

    Cadmium zinc telluride (CZT) detectors offer versatility, operational simplicity, and room-temperature X- and gamma-ray spectroscopy, making them attractive for collider applications, yet their use under high-flux conditions remains limited. Here, we present a preliminary feature-based pulse-shape analysis employing machine learning, on data acquired with a quasi-hemispherical CZT detector at the DANE beam test facility of the National Laboratory of Frascati of INFN. A 300-MeV electron beam impinging on a lead target produced characteristic Pb X-rays together with a broad background extending up to the electron-positron annihilation region. Physically motivated temporal and morphological features were extracted from the recorded waveforms and used to distinguish nominal photon-like pulses from anomalous events. An XGBoost classifier trained and validated on 10,000 labeled waveforms achieved an accuracy of approximately 97%, with most of its classification performance reached using only a few hundred labeled examples. The trained model was applied to more than 700,000 events, substantially reducing the spectral continuum and coincidence peaks, while preserving the characteristic Pb X-ray lines up to the 511-keV annihilation peak. These preliminary results demonstrate the potential of machine-learning-assisted pulse-shape discrimination for improving CZT spectroscopy in collider environments.

    ↳ physics.ins-detnucl-ex
  7. 07

    System-size dependence of bottomonium suppression from Pb-Pb to light-ion collisions

    Nora Brambilla · Tom Magorsch · Antonio Vairo

    We test the system-size dependence of bottomonium suppression using the same open-quantum-system transport framework for Pb-Pb, O-O, and Ne-Ne collisions. The microscopic transport coefficients are retained from previous Pb-Pb analyses. Using QTraj, we solve the next-to-leading-order pNRQCD Lindblad equation in anisotropic hydrodynamic backgrounds and calculate integrated double ratios. The QGP-induced evolution reproduces the observed sequential hierarchy and overall magnitude of the O-O suppression measured by CMS and LHCb. We quantify the sensitivity to both transport coefficients and to the termination temperature of the in-medium evolution. The Ne-Ne measurement favors somewhat stronger suppression than predicted, although the present experimental uncertainty is large. The extension from Pb-Pb to light ions supports, at least for observables less sensitive to cold nuclear matter effects, a common microscopic origin of bottomonium suppression in deconfined matter, characterized by the same temperature-dependent transport coefficients despite the large change in collision-system size.

    ↳ hep-phhep-exhep-latnucl-ex+1
  8. 08

    Scalable Terbium-149 Production from Highly Enriched Gadolinium-150 Targets

    J. F. Parisi · A. Rutkowski

    We propose a two-stage production method to overcome existing supply-constraints for the alpha-emitter Tb, a promising candidate for Targeted Alpha Therapy (TAT) with no existing globally scalable production pathway. Although awaiting experimental measurement of the Gd(p,2n)Tb cross section, the proposed method could produce Tb at clinical scale and beyond on readily available proton cyclotrons, enabled by production of the extinct but long-lived isotope Gd, a pure alpha emitter with a 1.79 million year half-life. Stage one generates Gd feedstock by irradiating natural Eu or enriched Eu with 10 MeV protons, neutrons or photons. Stage two produces Tb from fabricated Gd targets by driving the Gd(p,2n)Tb reaction with 14 MeV protons, accessible on over 700 reported cyclotrons worldwide. Fast fusion neutrons appear to offer the most scalable pathway for Gd production: even with a large Tb dose size of 1 GBq and 40 million administered doses/yr, we estimate this would require neutrons produced by only 6.8 megawatts of steady-state deuterium-tritium power to produce the required Gd, far below expected capacity in the next decade. The route described here, if validated, would enable Tb supply at the scale needed to support clinical development of Tb-based TAT.

    ↳ physics.plasm-phnucl-ex
  9. 09

    Towards real-time ion range verification via hybrid Compton-PET 3D imaging at isochronous cyclotrons

    Javier Balibrea-Correa · V. Babiano-Suarez · J. Lerendegui-Marco · P. Torres-Sánchez · I. Ladarescu · M. Pallàs · B. Brusasco · J. Wulff · C. Bäumer · A. Tarifeño-Saldivia · C. Domingo-Pardo

    Range uncertainties remain a major limitation to the full clinical exploitation of proton therapy, motivating reliable in-vivo range-verification techniques. This work presents an experimental investigation of a hybrid Prompt-Gamma Imaging (PGI)--Positron-Emission Tomography (PET) concept at the isochronous cyclotron of the West German Proton Therapy Centre under clinically representative pencil-beam-scanning conditions. Because this accelerator delivers a quasi-continuous beam, a pulsed shoot-and-step structure was imposed to mimic the interruptions associated with clinical energy-layer switching. This enabled PGI during irradiation and PET and delayed Compton imaging during beam-off intervals within the same sequence. Four two-plane Compton cameras were arranged in a co-planar cross-shaped geometry around the beam isocenter. Polyethylene phantoms were irradiated with 100~MeV protons at known positions along the beam axis. Their positions were estimated from reconstructed one-dimensional profiles using supervised machine-learning models trained exclusively on Monte Carlo simulations. PET achieved the best performance, with a root-mean-square deviation of 0.8~mm, followed by PGI with 1.6~mm. Delayed Compton imaging based on e annihilation photons and C decays yielded 2.4~mm and 3.8~mm, respectively. PET retained good performance down to 1% of the original event statistics, whereas PGI became increasingly statistics-limited. These results demonstrate the complementary strengths of hybrid PGI--PET and support its development towards millimetre-scale proton-range verification under clinically relevant irradiation conditions.

    ↳ physics.med-phnucl-ex