PaperPanorama

Nuclear Experiment·nucl-ex

Wed·Jun 24, 2026

5 papers—1 primary·4 cross-listed

All5Primary1Cross-lists4
  1. 01

    Measurements of Bremsstrahlung-Averaged Cross Sections for Reactions on Natural Nickel Targets at Eendpoint = 40MeV

    O. Nusair🇺🇸 · N. Solomon · M. Toro-Gonzalez · D. DeVries

    Bremsstrahlung activation measurements were performed to study the production of , , , , , and from natural nickel targets irradiated with photons generated by \SI{40}{MeV} electrons incident on a tantalum converter. Bremsstrahlung spectra were modeled using MCNP6.3\texttrademark{} and experimentally validated through activation of natural tin. Bremsstrahlung-averaged cross sections were extracted from end-of-irradiation activities, yielding ~mb for , ~mb for , ~mb for , ~mb for , and ~mb for . A confidence-level upper limit of ~mb is established for the channel. Comparison with JENDL-5 evaluations and prior studies indicates channel-dependent agreement, with residual discrepancies observed for selected charged-particle emission reactions. In particular, the measured cross section exceeds the JENDL-5 prediction by approximately a factor of two, whereas TALYS-2.2 calculations reproduce the experimental value, suggesting an underestimation of the channel strength in JENDL-5 under bremsstrahlung conditions. For the channel, both TALYS-2.2 and JENDL-5 predictions are in reasonable agreement, while the present measurement is higher by approximately a factor of two, though with larger associated uncertainty.

    nucl-exphysics.ins-detphysics.med-ph0 citations
  2. 02

    From Magnetic to Inverse Magnetic Catalysis: The Interplay of Quark and Gluon Mass Generation in Magnetic Fields

    Fei Gao🇨🇳 · Kairen Huang🇨🇳 · Yi Lu🇨🇳 · Yuxin Liu🇨🇳

    We analyze the effects of the magnetic field on the quark and gluon propagators within the functional QCD framework. By solving the coupled Dyson-Schwinger equations for the quark and gluon propagators, we find that the quark mass is generally enhanced in the presence of a magnetic field, leading to magnetic catalysis of the chiral condensate. Meanwhile, the magnetic field also induces an increase in the gluon screening mass. The enhancement of the gluon screening mass suppresses the quark-gluon interaction and thereby weakens the strength of dynamical chiral symmetry breaking, establishing a competing mechanism against magnetic catalysis. In particular, this enhancement of the gluon screening mass becomes dominant near the chiral phase transition, which in turn gives rise to inverse magnetic catalysis.

    ↳ hep-phhep-lathep-thnucl-ex+11 citation
  3. 03

    Polarized Deep-Inelastic Scattering with Spin Correlations in Herwig 7

    M.R. Masouminia🇬🇧 · A. Papaefstathiou🇺🇸 · P. Richardson🇬🇧

    We investigate polarized deep-inelastic scattering (DIS) in the context of fully exclusive Monte Carlo simulations for the Electron-Ion Collider (EIC). We present a next-to-leading-order (NLO) treatment of polarized DIS in HERWIG 7 using the POWHEG matching scheme, including neutral-current exchange and charged-current scattering. We also construct a spin-correlation treatment for NLO-matched events, first by initializing the shower from the spin-density matrix of the polarized DIS Born process and then by propagating the spin-density matrix of the accepted real-emission configuration without changing the POWHEG event weight or hardest-emission choice. We validate the integrated cross sections against fixed-order calculations, use parton-level comparisons without subsequent shower evolution to isolate the accepted POWHEG real-emission kinematics, and employ shower-level observables to test the numerical importance of the Born-level and real-emission spin information. We find that the Born-level spin-density initialization can have a visible impact on shower-sensitive observables, while the additional spin information from the accepted real-emission configuration is not resolved as a robust separate effect within the independent-sample Monte Carlo precision for the longitudinally polarized observables considered here.

    ↳ hep-phhep-exnucl-exnucl-th0 citations
  4. 04

    Mapping jet substructure in heavy-ion collisions with track functions

    João Barata🇨🇭 · Yeonju Go🇺🇸 · Daniel Pablos🇪🇸

    We investigate the dynamics of high-energy QCD cascades in heavy-ion collisions, focusing on modifications to jets' substructure induced by the presence of a quark-gluon plasma (QGP). To this end, we study the properties and scale evolution of track functions, non-perturbative objects encoding the flow of energy from an initiating parton to all charged hadrons. In contrast to the more standard fragmentation functions, these objects have a non-linear renormalization group (RG) evolution, being sensitive to the entire jet fragmentation process. Using the JEWEL and HYBRID Monte-Carlo models of jet quenching, we find that in both frameworks the higher moments and cumulants of the track functions' distributions exhibit sizable deviations from their vacuum baselines, demonstrating that medium-induced energy loss imprints itself in the in-medium jet fragmentation pattern. We find that the quantitative magnitude of these modifications differs significantly between the two models. This identifies track functions as a class of observables capable of discriminating between competing microscopic pictures of jet-medium interactions. We further examined the (in-medium) RG flows for the leading moments, which remain in qualitative agreement with the in-vacuum evolution. This provides an avenue to directly test the RG flows inside a QGP, linking heavy-ion jet measurements to basic QFT understanding of partonic branching. Finally, we comment on the feasibility and challenges associated with extracting track functions from experimental data.

    ↳ hep-phhep-exnucl-exnucl-th0 citations
  5. 05

    Anomalously long-delayed afterpulses in large-area photomultipliers

    Nikita Ushakov🇷🇺 · Bayarto Lubsandorzhiev🇷🇺 · Arslan Lukanov🇷🇺 · Andrei Sidorenkov🇷🇺 · Dmitrii Voronin🇷🇺

    We report the observation of anomalously long-delayed afterpulses in photomultipliers of the Baksan Large Neutrino Telescope project 10-inch R7081-100, 8-inch R5912-100, 20-inch R12860 photomultipliers produced by Hamamatsu Photonics, and 20-inch N6205 photomultipliers produced by NNVT. The mean delay times relative to the main pulses are approximately s, s, s, and s, respectively. The probability of such afterpulses does not exceed 0.1% per photoelectron, and their amplitudes are strictly confined to the single-photoelectron level, regardless of the amplitude of the main pulse. The delay time of these afterpulses shows no significant dependence on the PMT operating voltage.

    ↳ physics.ins-detastro-ph.IMhep-exnucl-ex0 citations

Affiliations

first authorsco-authorsvia INSPIRE