The intruder bands in Sn isotopes, built on the 2p-2h excitation across the $Z = 50$ proton shell gap, are well-known examples of shape coexistence near the neutron mid-shell region. Spectroscopic signatures for shape coexistence include enhanced $E0$ transitions between the $0^+$ band heads. However, the underlying shape coexistence and mixing has been unclear because lifetime information for the excited $0^+$ states was incomplete in $^{118}$Sn. We thus present here the first measurement of the $0^+_3$ lifetime in $^{118}$Sn using the fast-timing technique following thermal-neutron capture. The observed enhancement in $\rho^2(E0; 0^+_3 \rightarrow 0^+_2)$ of 150(30) milliunits provides compelling indications for multiple shape coexistence in $^{118}$Sn. Additionally, three distinct shapes in $^{116,118,120}$Sn naturally emerged in theoretical calculations based on the quantum-number-projected generator coordinate method employing a relativistic energy density functional.

The Internal Conversion Electron SPectrometer In Coincidence Experiments (ICESPICE) demonstrator has been developed at Florida State University to enable particle/gamma-electron coincidence measurements in low-energy nuclear structure studies. ICESPICE is based on the mini-orange spectrometer concept and features a modular design using commercially available permanent magnets arranged in toroidal configurations to transport internal conversion electrons to room-temperature PIPS detectors while suppressing background from undesired particles. The system was optimized through SolidWorks modeling, COMSOL magnetic field simulations, and Geant4 particle tracking to maximize the magnetic transmission probability for electrons around 1 MeV. Commissioning tests using a calibrated 207Bi source demonstrated the performance of multiple spectrometer-detector configurations. Coincidence measurements between CeBr3 detectors from the CeBrA array and PIPS detectors revealed clear gamma-electron correlations. The first in-beam particle-electron measurements using ICESPICE were performed with the Super-Enge Split-Pole Spectrograph (SE-SPS) in the 208Pb(d,t)207Pb reaction. Prompt coincidences between tritons detected with the SE-SPS and electrons detected with ICESPICE were observed. The presented results show that ICESPICE is a promising ancillary detector system for in-beam internal conversion electron spectroscopy at the FSU SE-SPS.

Symmetry-violating observables such as the nuclear anapole and Schiff moments provide sensitive probes of the fundamental symmetries of nature and physics beyond the Standard Model. Their interpretation has been hindered, however, by the lack of ab initio nuclear structure calculations in the medium-mass and heavy nuclei of interest to experimentalists. To provide them, we introduce a new version of the in-medium similarity renormalization group (IMSRG) designed to target parity-violating operators. By generalizing the IMSRG flow equations to evolve the weak symmetry-breaking Hamiltonian - and the anapole or Schiff operators - alongside the strong nuclear Hamiltonian, we construct a systematically improvable framework for computing these parity-violating moments. We benchmark the method against the no-core shell model in light nuclei and obtain the first ab initio predictions of the anapole moment in $^{29}$Si and the Schiff moments in $^{129}$Xe. These heavier systems are of direct experimental interest.

The CEBAF Large Acceptance Spectrometer for operation at 12 GeV (CLAS12) at the Thomas Jefferson National Accelerator Facility has played a central role in advancing the understanding of nucleon and nuclear structure. As increasingly precise data become available, new physics opportunities emerge that extend beyond the current capabilities of CLAS12. In this article, a program to explore the quark and gluon structure of the nucleon through di-muon electro- and photoproduction is presented. Its primary focus is the measurement of beam-spin asymmetries in Double Deeply Virtual Compton Scattering, $ep \rightarrow e^\prime \mu^+ \mu^-p^\prime $. By independently varying the incoming and outgoing photon virtualities and momentum transfer, the DDVCS measurement provides access to the Generalized Parton Distributions over their full three-dimensional phase space, extending beyond the kinematic constraints of Deeply Virtual Compton Scattering and Timelike Compton Scattering. In addition, the large acceptance and high luminosity of the $\mu$CLAS12 experiment will enable precision measurements of near-threshold $J/\psi$ production and high-statistics studies of Timelike Compton Scattering.

The photoproduction of $J/\Psi$ in peripheral Oxygen - Oxygen ($OO$) collisions at the Large Hadron Collider (LHC) is investigated considering distinct assumptions for the modeling of the nuclear photon flux, overlap function and dipole - proton scattering amplitude. Predictions for the associated rapidity distributions and total cross - sections are presented. Our results indicate that the experimental study of the photoproduction of $J/\Psi$ in peripheral $OO$ collisions is, in principle, feasible. In addition, they point out that the combination of the results for this final state in $OO$ collisions with those obtained for $PbPb$ collisions will allow us to derive important constraints on the description of photon - induced process at peripheral collisions.

The higher-twist formalism is used at $O(\alpha^2_s)$ to compute all possible medium-induced single-scattering emission kernels for an incoming highly energetic and virtual quark traversing the nuclear environment. The effects of the heavy-quark mass scale are taken into account [Phys. Rev. C 94, 054902 (2016)] both in the initial state as well as in the final state, along with interactions involving both in-medium Glauber gluons and quarks [Nucl. Phys. A 793, 128 (2007)], as well as coherence effects [Phys. Rev. C 105, 024908 (2022)]. As this study is a continuation of our work on medium-induced photon production [Phys. Rev. C 112, 025204 (2025)], the general factorization procedure for $e$-$A$ deep-inelastic scattering is still used. An incoming quark energy loss in the nuclear medium yields four possible scattering kernels $K_i$ with the following final states: (i) $q+g$, (ii) $g+g$, (iii) $q+\bar{q}'$, where the quark $q$ may have a flavor different from the antiquark $\bar{q}'$, and (iv) $q+q'$, where, again, $q$ may have a flavor different from $q'$. The collisional kernels include full phase factors from all non-vanishing diagrams and complete first-order derivative in the longitudinal direction ($k^-$) as well as second-order derivative in the transverse momentum ($k_{\perp}$) gradient expansion. Furthermore, in-medium parton distribution functions and the related jet transport coefficients have a hard transverse-momentum dependence (of the emitted quark or gluon) present within the phase factor.

We study the order-by-order expansion of the energy per particle of asymmetric nuclear matter up to twice saturation density in chiral effective field theory (EFT) within a Bayesian framework. For this, we develop a two-dimensional Gaussian process (2D GP) that is trained using many-body perturbation theory results based on chiral two- and three-nucleon interactions from leading to next-to-next-to-next-to-leading order (N$^3$LO). This allows for an efficient evaluation of the equation of state (EOS) and thermodynamic derivatives with EFT truncation uncertainties. After benchmarking our 2D GP against Bayesian uncertainties for pure neutron matter and symmetric matter, we study the energy per particle, pressure, and chemical potentials of neutron star matter in $\beta$-equilibrium including EFT uncertainties. We investigate the phase diagram of neutron-rich matter from neutron- to proton-drip and to the uniform phase, including surface and Coulomb corrections. Based on this, we construct EOSs for the inner crust of neutron stars that are consistent with the chiral EFT results for uniform matter at N$^3$LO.

The Particle-Identification Silicon-Telescope Array (PISTA) is a new detection system designed for high-resolution studies of the fission process induced by multi-nucleon transfer in inverse kinematics. It is specifically optimized for experiments with the VAMOS++ magnetic spectrometer at GANIL (Grand Accélérateur National d'Ions Lourds). The array comprises eight trapezoidal $\Delta$E-E silicon telescopes arranged in a corolla configuration. Each telescope integrates two single-sided stripped silicon detectors, enabling target-like recoil identification, energy loss measurements, and trajectory reconstruction. Positioned in close proximity to the target, PISTA's compact geometry achieves high-efficiency tracking of target-like recoils produced in multi-nucleon transfer reactions at Coulomb barrier energies. The spatial segmentation of the array allows precise determination of the mass and charge of the target-like nucleus, and excitation energy of fissioning systems. This work presents the particle identification and excitation energy reconstruction performances for the interactions of $^{238}$U beam with $^{12}$C target. An excitation energy resolution of 800 keV (FWHM) was determined together with mass resolution of 1.1% (FWHM). The combination of PISTA and VAMOS++ magnetic spectrometer enables unprecedented investigations of the fission process as a function of the excitation energy of the fissioning nucleus, particularly for exotic systems produced in transfer-induced reactions.

PICOSEC is an ultrafast particle-detector concept, combining a photocathode-coated Cherenkov radiator coupled to a gas-avalanche multiplier. Particle-induced Cherenkov photons create photoelectrons emitted from an ultrathin semitransparent photocathode; they are multiplied and detected in fast gas-avalanche mode. In parallel to the constant progress made in the PICOSEC technique, we propose different detector configurations and operation modes with the aim of enhancing robustness and performance. They incorporate thick reflective photocathodes deposited on the readout electrodes of various types of avalanche multipliers. Some of these Reflective-PICOSEC detectors operate at mbar gas pressures.