PaperPanorama

Nuclear Experiment·nucl-ex

Thu·Oct 8, 2026

5 papers—1 primary·4 cross-listed

All5Primary1Cross-lists4
  1. 01

    Event-by-event net-charge fluctuations in pp, OO, Ne-Ne, and Pb-Pb collisions with ALICE at the LHC

    Nida Malik

    Investigations involving the event-by-event fluctuations of conserved quantities, like net charge, net baryon number, and strangeness in heavy-ion collisions, provide insights into the properties of quark-gluon plasma (QGP) and the phase diagram of strongly interacting matter. Event-by-event fluctuations of net electric charge in pp collisions at and TeV and for OO, Ne-Ne, and Pb-Pb collisions at TeV are studied by analysing the data collected by the ALICE detector at CERN Large Hadron Collider. The analysis is carried out in terms of the variable , chosen for its robustness against detector efficiency losses. The observed dependence of on the charged-particle density shows a smooth, energy-independent decrease in the magnitude of from smaller to larger collision systems. The negative values of indicate a dominance of correlations between oppositely charged particle pairs compared with those arising from like-sign charge pairs. Since is known to have an intrinsic dependence on multiplicity, an appropriate scaling is applied. The variable is therefore scaled with the mean multiplicities, . The dependence of the scaled values of on charged particle density is also looked into. The results are compared with model calculations from PYTHIA, EPOS4, AMPT and HIJING.

    nucl-ex
  2. 02

    A Differentiable Surrogate for Loss-Dominated Ion Beam Transport

    Jose M. Munoz-Arias · Laura Ruiz-Arango · Derick Gonzalez-Acevedo · Fabian C. Pastrana-Cruz · Jackson Hacias · Ronald F. Garcia Ruiz

    Radioactive nuclei with extreme proton-to-neutron ratios provide unique probes of nuclear structure, fundamental symmetries, astrophysical processes, and applications such as medicine. However, their short half-lives and low production rates mean that experiments must work with few desired ions, often amid contaminant backgrounds exceeding the signal by six orders of magnitude. Efficiently isolating, transporting, and delivering these ions through multi-stage apparatus is therefore a central challenge. We introduce a differentiable probabilistic surrogate for ion-beam transport in regimes dominated by particle loss. The model jointly captures the survival probability of ions along the beamline and the evolving phase-space distribution of the surviving particles by combining discrete-time survival analysis with conditional normalizing flows. Applied to a high-dimensional electrostatic beamline, the resulting likelihood enables gradient-based optimization of operating voltages and inference of beam properties from sparse detector observations. Once trained, the surrogate provides millisecond-scale differentiable predictions, transforming particle-tracking simulations with hard losses into an inference-ready model for experimental design, beamline optimization, and future digital twins of experiments with rare nuclei.

    ↳ physics.ins-detnucl-ex
  3. 03

    Novel chiral-wobbling excitation mode in atomic nuclei

    Kouser Qureshie · S. P. Rouoof · J. A. Sheikh · Nazira Nazir · G. H. Bhat · S. Jehangir · N. A. Rather · R. J. Guo · S. Y. Wang · C. Liu · Q. B. Chen · S. Frauendorf

    The properties of high-spin band structures in Br nucleus are investigated using the triaxial projected shell model (TPSM) and particle triaxial rotor (PTR) approaches. It has already been demonstrated that lowest three bands observed in Br have a characteristic feature of a chiral-wobbler. The first excited band is the chiral partner of the yrast band and the second excited band is the wobbling band based on the yrast state. We have analyzed the third excited band using the TPSM and PTR calculated quantities, and a unique character of this band is revealed. It is predicted that this band is the chiral partner of the second excited band, and is also a wobbling mode based on the first excited band.

    ↳ nucl-thnucl-ex
  4. 04

    Tensor-structure sum rules for spin-1 targets at all

    Vladimir Pascalutsa · Marc Vanderhaeghen

    We derive a family of sum rules for the tensor structure functions of targets with spin one or higher, rooted in exact Siegert relations. The mixed rank-two -- degeneracy combines amplitudes of opposite crossing parity and, under the superconvergence assumption, gives in the Hoodbhoy--Jaffe--Manohar (HJM) basis. At large , the protected moment agrees with Detmold's target-mass-complete twist-two OPE; in the strict Bjorken projection, and if is neglected, it reduces to the Efremov--Teryaev (ET)-type condition , whose measured-range footprint is consistent with the HERMES data. Two further rank-two combinations connect crossing-even amplitudes and determine the corresponding subtraction functions through weighted HJM moments. The protected combination can be isolated through separated tensor and responses, providing a direct experimental strategy for JLab and, ultimately, a future EIC.

    ↳ hep-phhep-thnucl-exnucl-th+1
  5. 05

    Timing Challenges in Transmission Silicon Detectors for Light Ions

    Diego Tarrio · Friedrich Karl Moraht · Lucas de Arruda · Stephan Pomp · Xavier Ledoux · Diego Ramos

    Transmission silicon detectors are widely used in -- telescope configurations for particle identification and timing in nuclear physics experiments. Variations in signal rise time can introduce time-walk effects that degrade time-of-flight measurements, as recently observed in light-ion production experiments at the Neutrons For Science (NFS) facility at GANIL using the Medley setup. This work investigates the influence of particle energy and detector non-uniformity on signal rise time.

    ↳ physics.ins-detnucl-ex