PaperPanorama

Nuclear Experiment·nucl-ex

Fri·Sep 11, 2026

6 papers—2 primary·4 cross-listed

All6Primary2Cross-lists4
  1. 01

    Island of Inversion in neutron-rich cobalt isotopes revealed from mass measurements

    M. Flayol · P. Ascher · D.D. Dao · M. Gerbaux · S. Grévy · F. Nowacki · A. de Roubin · D. Atanasov · B. Blank · L. Canete · Q. Délignac · T. Eronen and 10 other authors

    Mass measurements of the ground and isomeric states of Co have been performed using the JYFLTRAP Penning-trap mass spectrometer at the IGISOL facility. The masses were measured, either for the first time for the isomeric states of Co and Co, or with greatly improved precision for the others, removing ambiguities in the mass surface beyond . The ordering of the low and high-spin states in Co and Co has also been established. The results, supported by Large-Scale Shell Model and Discrete Non-Orthogonal Shell-Model calculations, show a gradual lowering of intruder states with increasing neutron number, eventually leading to an inversion in Co. These findings clarify previously proposed contradictory interpretations. Finally, we demonstrate the importance of including induced effective 3N forces for a consistent description of binding energies in the island of inversion near .

    nucl-ex
  2. 02

    A detailed view at magnetic dipole strengths: The case of semi-magic Ti

    B. Kelly · M. Spieker · U. Friman-Gayer · L. T. Baby · T. Beck · A. L. Conley · S. W. Finch · J. Isaak · Krishichayan · E. Litvinova · H. Pai · N. Pietralla and 5 other authors

    Magnetic dipole, , strengths were studied in semi-magic Ti up to the neutron-separation threshold by combining data from one-neutron transfer, real-photon scattering, inelastic scattering at extreme backward angles, and at MeV and extreme forward angles. The combination of all probes provided unique access to the neutron spin-flip contribution and the possibility to evaluate its role in generating the spin-flip strengths. The small contribution of the neutron spin-flip transitions, which were probed with the reaction, to the overall strength in Ti questions the standard picture for the microscopic origin of spin-flip strength in the shell. For Ti, this letter shows that states with larger neutron spectroscopic factors do not correspond to the ones with the largest strengths.

    nucl-exnucl-thPhys. Rev. Lett. 136, 082502 (2026)
  3. 03

    Production of Light Nuclei and Hypernuclei in Heavy-Ion Collisions

    Guannan Xie · Yue-Hang Leung

    We review recent STAR and ALICE measurements of light-nucleus and hypernucleus yields, femtoscopic correlations, and collective flow presented at SQM 2026. Statistical-hadronization calculations provide a useful baseline for integrated yields but do not simultaneously describe all measured light-nucleus ratios across collision energies and system sizes. For bound states with mass number , current coalescence calculations provide a broadly consistent description of yields, femtoscopic correlations, and collective flow, although the quantitative hypertriton comparison depends on the assumed few-body wave function. The suppressed production of resonant Li relative to compact He indicates an effect of nuclear structure and late-stage dynamics. However, the quantitative model comparison also depends on the treatment of feed-down from unstable states. In high-multiplicity + collisions, pion-deuteron femtoscopy further indicates that most observed (anti)deuterons are formed through nucleon fusion after strong decays of short-lived resonances. Taken together, these measurements show that production chronology and internal nuclear structure leave measurable imprints on the physics observables.

    ↳ hep-exnucl-ex
  4. 04

    Qubit-Qutrit Quantum Tomography of hadronic and systems

    Veronica Kanachova · Feng Liu · Zhoudunming Tu

    Quantum-information observables have emerged in recent years as new tools in nuclear and particle physics, from entanglement in top-quark pairs to spin correlations in production. Extending these studies to unequal-spin hadronic final states poses a fundamental challenge: the density matrix of a qubit-qutrit system contains 35 independent spin parameters, but the decays of pairs, with or , provide access to only 23 due to the hidden vector polarization from the strong decay. In this Letter, we formulate a qubit-qutrit quantum tomography (QQQT) technique for these spin- systems and establish exact criteria for entanglement certification from the \textit{incomplete} density matrix. Compared with the system, QQQT of and provides a new probe of nonperturbative QCD hadronization, enabling a direct comparison of the spin evolution of entangled quark pairs produced from the vacuum as they hadronize into a baryon or a vector meson.

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

    Study of the multiplicity dependence of non-flow correlations in pp collisions at GeV using PYTHIA

    Milan Stojanovic · Joern Putschke

    The observation of a near-side enhancement in long-range correlations within high-multiplicity pA and pp collisions, commonly referred to as the ridge, has motivated significant efforts to quantify possible collective effects in small systems. Estimation of non-flow contributions in two-particle correlation measurements in small systems at the LHC typically relies on the assumption that jet-induced non-flow correlations are independent of event multiplicity. Consequently, this assumption allows the high-multiplicity non-flow to be estimated and accounted for by directly using low-multiplicity events. In this paper, the validity of this assumption is studied examining the multiplicity dependence of non-flow contributions estimated via two-particle correlation functions in pp collisions at RHIC energies ~GeV using the PYTHIA event generator. It is observed that selecting any specific multiplicity range inherently biases jet production dynamics. These biases introduce a non-trivial multiplicity dependence of the non-flow contribution at RHIC energies. The dependence of jet fragmentation and -differential cross sections on event multiplicity is studied using a variety of commonly used multiplicity estimators, including mid-rapidity charged-particle multiplicity, forward multiplicity, and underlying-event activity. The results indicate that non-flow contributions do not exhibit simple multiplicity scaling and challenge the applicability of standard subtraction procedures utilized at LHC energies at lower RHIC collision energies.

    ↳ nucl-thnucl-ex
  6. 06

    Collinear fragmentation of pseudoscalar quarkonia from NLO NRQCD

    Francesco Giovanni Celiberto · Francesca Lonigro

    We discuss a new family of publicly available collinear fragmentation functions (FFs) for pseudoscalar quarkonia, the NRFF1.0 set. It builds upon the Heavy-Flavor Non-Relativistic evolution (HF-NRevo) scheme, designed to describe heavy-hadron formation through leading-power fragmentation at moderate and large transverse momentum. Heavy-quarkonium production naturally involves both perturbative and non-perturbative QCD dynamics, from the production of the heavy pair to its formation into a physical bound state. Within NRFF1.0, Non-Relativistic Quantum Chromodynamics (NRQCD) provides the theoretical framework for calculating the FF inputs at the initial scale, which are subsequently evolved through the HF-NRevo scheme. This setup provides a precision baseline for investigating the underlying partonic hierarchy and jet structure across the moderate- to high-transverse-momentum regime. The explicit treatment of partonic channels and heavy-flavor thresholds makes this framework particularly suitable for exploring quarkonium-in-jet fragmentation, jet-quenching sensitivity, energy-loss mechanisms, and the emergence of medium-modified fragmentation patterns in the quark-gluon plasma.

    ↳ hep-phhep-exhep-thnucl-ex+1