PaperPanorama

Nuclear Experiment·nucl-ex

Wed·Oct 14, 2026

5 papers—1 primary·4 cross-listed

All5Primary1Cross-lists4
  1. 01

    Letter of Intent for Alpha Knockout from Nuclei in Hard Exclusive Processes with ALERT

    Whitney R. Armstrong† · Ian Cloët · Fernando A. Flor · Sylvester Joosten Bobae Kim · Minho Kim · Henry T. Klest · Zein-Eddine Meziani · Chao Peng · Valerii Klimenko · Noémie Pilleux · Maria Żurek · Jacob C. Dulya and 12 other authors

    We propose to measure hard exclusive -knockout reactions from the light -conjugate nuclei C, O, and Ne using electron scattering. Three reaction channels will be measured for the first time on the same target set: (i) the quasi-elastic knockout knockout, which establishes a baseline against -clustering model calculations and tests final-state-interaction (FSI) models; (ii) coherent deeply virtual Compton scattering (DVCS) on a bound , which provides a quark-level probe of the bound system through the beam-spin asymmetry; and (iii) coherent vector-meson production ( and J/{}) on a bound , which probes the gluon distribution of the bound cluster through two-gluon exchange. The central observables are ratios of cross sections and beam-spin asymmetries between the bound in C, O, and Ne and the free He ground state. Together these measurements directly address the question of the role of QCD in the structure of light nuclei : do the quark and gluon distributions of an embedded in a heavier nucleus differ from those of a free 4He, and do those modifications track the increasing -clustering strength along the -conjugate chain? The measurement will use the 12 GeV CEBAF accelerator in Hall B with the CLAS12 spectrometer instrumented with the ALERT low-energy recoil detector and high-pressure gas straw targets. ALERT, which replaced the CLAS12 silicon vertex tracker, was successfully commissioned and operated during Run Group L (RG-L) from April through August 2025. It uniquely provides identification of low-momentum recoiling light ions (p, d, t, He, and He) close to the beamline at the high luminosities required by these exclusive channels.

    nucl-ex
  2. 02

    Competitive constraints on exotic tensor currents from ratios

    Victor Dumenil · Leendert Hayen

    We introduce the ratio of electron capture to positron decay rates of unstable nuclei as a probe for exotic tensor currents in the electroweak sector. We calculate nuclear structure corrections and newly derived radiative corrections and obtain competitive limits on exotic tensor couplings using historically available data to find which is competitive with collider searches and the global -decay database. In doing so, we resolve a 50-year-old tension in the strongly hindered Na transition by retaining higher-order operators, obtaining a consistent description of its different weak-decay observables. Finally, we discuss the potential of this method to significantly improve tensor constraints using modern cryogenic quantum sensors.

    ↳ nucl-thnucl-ex
  3. 03

    Deconfinement and the Charge Susceptibility Matrix of QCD

    Christopher Grace · Brady Mowbray · Christopher Plumberg

    At sufficiently high temperatures, lattice Quantum Chromodynamics (QCD) calculations predict that nuclear matter undergoes a rapid crossover to a novel, deconfined state known as the quark-gluon plasma (QGP), in which quark flavors essentially behave like independent particles. Here we explore the nature of this transition by introducing two new thermodynamic observables which we refer to as the diagonality and the rescaled curvature of the QCD equation of state (EoS). By comparing these observables in the case of lattice QCD calculations with those of simple toy models and more sophisticated hadronic resonance models, we show that both the diagonality and the rescaled curvature provide complementary insights into the degree of independence between different quark flavors and the underlying degrees of freedom in the system as functions of temperature. We propose that these observables may help to clarify the nature of the transition region and the onset of deconfinement in nuclear matter.

    ↳ nucl-thnucl-ex
  4. 04

    Response of GAGG(Ce) scintillators to different charged particles

    Kai-Jie Zhou · Zai-Hong Yang · Hooi-Jin Ong · Qi-Te Li · Ze-Yu Du · Jia-Wei Bian · Cheng Wang · Jin-Ning Li · Satoru Terashima · Bing-Feng Lv · Xuan Wang · Zhi-Chao Zhang and 4 other authors

    Charged-particle telescopes play an essential role in studies of nuclear clustering, which require high-resolution detection of charged breakup fragments. GAGG(Ce) is a promising scintillator for charged-particle detection at high counting rates because of its high light yield, fast response, and non-hygroscopic nature. However, systematic data on its light-output response to different charged particles remain scarce. In this work, we present a systematic study of the scintillation light-output response of GAGG(Ce) crystals to various charged particles and quantify the associated quenching behavior. The relationship between the scintillation light output and the deposited energy is established over a broad range of particle species and energies, providing essential experimental input for response modeling and energy calibration of GAGG(Ce)-based charged-particle detector systems.

    ↳ physics.ins-detnucl-ex
  5. 05

    Higher-order corrections to beta decays and nuclear structure

    Grigor Sargsyan · Ayala Glick-Magid

    Precision measurements of nuclear decay offer a powerful route to tests of physics beyond the Standard Model, but interpreting measurements spectra and correlation observables requires control of subtle nuclear-structure effects. This chapter develops a framework for calculating higher-order corrections--small contributions that can become important at the precision sought in searches for new interactions. After motivating their role in -decay observables (with radiative corrections treated in the accompanying chapter), we introduce the relevant kinematics and multipole expansion of the shape factor, identify the subleading contributions, and present the impulse-approximation multipole operators. We then describe the nuclear many-body methods used to obtain the required states and transition densities, and derive the corresponding operator matrix elements in the harmonic-oscillator basis. Taken together, these ingredients enable systematic calculations of nuclear shape factors beyond the long-wavelength approximation, including higher-order multipoles where needed. By helping distinguish Standard-Model recoil effects from possible signatures of new physics, this framework supports the interpretation of increasingly precise -decay experiments.

    ↳ nucl-thnucl-ex