PaperPanorama

Nuclear Experiment·nucl-ex

Fri·Jul 10, 2026

7 papers—1 primary·6 cross-listed

All7Primary1Cross-lists6
  1. 01

    A study of neutrinoless double electron capture in Ca from the AMoRE experiment

    AMoRE Collaboration: A. Agrawal · V.V. Alenkov · P. Aryal · J. Beyer · B. Bhandari · R.S. Boiko · K. Boonin · O. Buzanov · C.R. Byeon · N. Chanthima · M.K. Cheoun🇰🇷 · J.S. Choe and 97 other authors

    The search for neutrinoless double electron capture () provides a sensitive probe of lepton-number violation and the Majorana nature of neutrinos. We investigate the decay of Ca using cryogenic detectors equipped with metallic magnetic calorimeters in the AMoRE-I experiment. The analysis is based on a physics dataset corresponding to a total exposure of 7.32 kgyr from thirteen CaMoO crystals. No significant excess is observed, and a lower limit on the half-life is obtained as yr at 90 confidence level. An improved sensitivity is expected for the upcoming AMoRE-II experiment. These results demonstrate the potential of CaMoO detectors to explore rare decay processes beyond the primary Mo search program.

    nucl-exhep-ex0 citations
  2. 02

    Impact of QED Radiation on SMEFT Constraints in Deep Inelastic Scattering

    Sonny Mantry🇺🇸 · Jian-Wei Qiu🇺🇸 · Jia-Yue Zhang🇺🇸

    Deep-inelastic scattering (DIS) provides a powerful probe of physics beyond the Standard Model through precision measurements interpreted within the Standard Model Effective Field Theory (SMEFT). We study the impact of collision-induced QED radiation on SMEFT constraints using the joint QCD+QED factorization framework based on lepton distribution and fragmentation functions. QED radiation can substantially modify DIS cross sections and, in some kinematic regions, significantly alter the effective momentum transfer relevant for factorization. We find that while cross sections receive order-one corrections, longitudinal electron spin asymmetries are affected only at the few-percent level, making them significantly more robust observables for SMEFT studies. Benchmark projections for SoLID and the Electron-Ion Collider are provided to demonstrate the impact of QED radiation for future precision DIS analyses and the extraction of SMEFT constraints.

    ↳ hep-phhep-exnucl-ex0 citations
  3. 03

    Node-locked phase of annual modulations from the gravitational chiral anomaly in the solar Kerr field

    M. Misiaszek🇵🇱

    The leading parity-odd mass--spin curvature invariant of the solar exterior, , changes sign when the Earth crosses the solar equatorial plane and acts as the geometric source of the gravitational chiral anomaly. We study two minimal phenomenological responses to this structure: a long-memory reservoir and the local worldline derivative . Both have an annual Fourier phase fixed by ephemerides, ~d (June 7--8) or the opposite branch ~d, with a calculable secular drift of ~d\,yr and an energy-independent geometric input phase, while predicting different semiannual fractions, and , respectively. The response amplitudes and their microscopic origin are not predicted; the phase is. Single-amplitude fits to the digitized DAMA/LIBRA--phase2 1--3~keV residuals give for the reservoir and for the derivative, against for the standard-halo cosine. The most precise published phase, ~d, lies from the halo value and from the node-locked one; phase metrology at the two-day level (), together with the phase-locked semiannual component, discriminates between the two clocks.

    ↳ astro-ph.SRnucl-ex0 citations
  4. 04

    Experimental access to the gluonic origin of the proton mass

    Zein-Eddine Meziani🇺🇸 · Ismail Zahed🇺🇸

    Most of the proton mass originates not from the Higgs mechanism but from the quantum structure of the QCD vacuum. The dominant contribution arises from the gluonic trace anomaly associated with the breaking of conformal symmetry in quantum chromodynamics. We show that this anomaly contribution is experimentally accessible through scalar gravitational form factors. The key observable is the scalar gluonic trace form factor of the proton, which can be reconstructed from three measurable quantities: the quark scalar gravitational form factor accessible in deeply virtual Compton scattering, the gluon scalar gravitational form factor measurable in near-threshold heavy quarkonium production, and the nucleon sigma-term form factor. We also show that the scalar gluonic form factor extracted from the trace anomaly is quantitatively consistent with lattice QCD and the instanton liquid model over hadronic distance scales. These results provide a direct experimental path to probing the gluonic origin of visible mass.

    ↳ hep-phnucl-ex0 citations
  5. 05

    Microscopic description of C+C fusion reactions at nuclear astrophysical energies

    K. Nagao🇯🇵 · K. Hagino🇯🇵 · K. Uzawa

    The C + C fusion reaction plays a key role in several astrophysical phenomena. However, it is difficult to determine its cross sections in the relevant energy region because of both low cross sections and strong resonant structures. On the other hand, the C + C system shows a much smoother energy dependence of fusion cross sections. To simultaneously analyze the C + C systems, we here develop a reaction model that explicitly treats the entrance channel and the compound nucleus states. For this purpose, we combine the discrete basis model for the entrance channel and the shell model for the compound nuclei. The coupling strengths between the entrance channel and the compound nucleus states are determined so that the fusion cross sections for these systems match with each other at the resonance energies for the C + C system, as has been observed experimentally. The model successfully reproduces the significantly different behaviors of fusion cross sections in these systems.

    ↳ nucl-thastro-ph.SRnucl-ex0 citations
  6. 06

    Lectures on lepton-nucleus quasielastic scattering with relativistic models

    Raúl González-Jiménez🇪🇸

    In these notes, basic concepts and necessary formulas for the modeling of elastic lepton-nucleon and quasielastic lepton-nucleus scattering using relativistic models are discussed. Certain theoretical developments are presented in meticulous detail, particularly those rarely found in papers or standard textbooks. In order to highlight the discrepancies between models and evaluate the impact of various nuclear effects, theoretical predictions are compared with inclusive electron scattering data. These notes are designed for Master's or PhD students embarking on their research in the field of neutrino-nucleus interactions at intermediate energies (ranging from several hundred MeV to a few GeV). They are intended to serve as a supplemental guide, never as a substitute for traditional textbooks on Scattering Theory and Quantum Field Theory. Currently, these notes are included in the course `Relativistic Quantum Theory: Nuclear Processes', which is integrated into both the Interuniversity Master in Nuclear Physics (https://master.us.es/fisicanuclear/index.php/) and the Erasmus Mundus Joint Master Degree in Nuclear Physics (https://www.emm-nucphys.eu/en), with the University of Seville as one of the partner institutions. Previously, this material was part of the course `Weak Interactions', within the same Master's programs.

    ↳ nucl-thhep-exhep-thnucl-ex0 citations
  7. 07

    Secondary Hadron--Nucleus Collisions of Short-Lived Hadrons in Ultra-Relativistic Fixed-Target Heavy-Ion Interactions

    Sanatan Digal🇮🇳 · P. S. Saumia · Ajit M. Srivastava🇮🇳

    Ultra-relativistic heavy nuclei traversing a solid target undergo successive nuclear encounters separated by atomic lattice spacings. At sufficiently high beam energies, Lorentz contraction reduces the proper time between collisions to ~fm in the center-of-mass frame of the first interaction. We then consider the fragmentation region of this first collision, and show that short-lived hadrons produced in this region, with additional Lorentz boost, can reach the next nucleus before decaying. We show that this geometry enables secondary hadron--nucleus collisions involving species that cannot be realized as conventional secondary beams or in subsequent hadron--nucleus interactions in cosmic-ray cascades. For a TeV-per-nucleon Pb beam incident on a solid Pb lattice, we determine which forward-produced hadrons can survive to a second interaction, estimate their collision probabilities, and analyze potential observable consequences. In particular, we identify some representative hadrons whose proper lifetimes are of order fm/c, e.g. specific mesons () and heavy-flavor resonances (), as projectile species that become accessible through this collision space-time geometry. At substantially higher beam energies (for example, with 10 TeV per-nucleon Pb beam), the survival probabilities are significantly enhanced. This can make even very short lived hadrons with life times of few tens fm ( , , ) available for this secondary hadron-nucleus collision, providing an additional motivation for future ultra-relativistic fixed-target heavy-ion experiments.

    ↳ nucl-thnucl-ex0 citations

Affiliations

first authorsco-authorsvia INSPIRE