Observation of the 511-keV positron-annihilation line would be a powerful probe of classical novae, with the primary source of positrons likely from the $\beta^+$ decay of \textsuperscript{18}F. We have determined the properties of important resonances in $^{19}$Ne which govern the \textsuperscript{18}F($p,\alpha$)\textsuperscript{15}O reaction rate and the production of \textsuperscript{18}F in novae. Measured $\alpha$ and proton angular distributions from states populated in the \textsuperscript{19}F(\textsuperscript{3}He,$t$)\textsuperscript{19}Ne reaction identified six near-threshold proton $s$-wave \textsuperscript{18}F$+p$ ($L_p=0$) states, and the asymptotic normalization of these states was studied using the symmetry-adapted no-core shell model. We have improved our understanding of states contributing to the \textsuperscript{18}F($p,\alpha$)\textsuperscript{15}O reaction rate and show that earlier studies significantly underestimated the uncertainties.

Comparison of two probability density/mass functions (PDF/PMFs) is ubiquitous in various forms of scientific analysis, including machine learning, optimization problems, and hypothesis tests. A copious amount of distance metrics have already been proposed and are regularly being used in this regard. In this document, we report a data-driven systematic comparison among a few of such metrics. The metrics considered here are Hellinger distance, Wasserstein distances (1D), $\sqrt{JS}$ distance, $L_\infty$ norm, Kolmogorov-Smirnov distance, and Fisher-Rao metric. We perform this comparison using electron and photon events from a decaying \iso{Kr}{83} isotope, collected through an HPGe spectrometer operating under cryo-vacuum conditions. To accomplish this, first, a dimensionless Parameter of Interest (PoI) was established, then PDF/PMFs were generated from the data, and finally the stabilities of the PoI under various criteria, such as sample size, discretization length, and normalizing functions, were studied and the results were summarized. In this report, we also propose a list of properties that a normalizing function should have and utilize them in the comparison.

Neutrinoless double beta decay is a hypothetical nuclear transition whose observation would demonstrate that neutrinos are their own antiparticles and that lepton number is not conserved, with far-reaching implications for the origin of neutrino mass and the matter-antimatter imbalance in the Universe. This review examines the theoretical foundations of this process and surveys the principal experimental strategies developed to search for it, focusing on their operating concepts, strengths, and limitations. We summarize the current experimental landscape by presenting the most sensitive results achieved so far and by outlining the complementary approaches pursued by different detection techniques. Finally, we discuss the future direction of the field, emphasizing the technological advances needed to reach substantially better sensitivities and, ultimately, to detect this rare phenomenon

The spectroscopy of $^{11}$Be is explored using the $^{10}$Be$(d,p)$$^{11}$Be transfer reaction performed in inverse kinematics at $9.6\,\MeV/u$ using the Active Target Time Projection Chamber (AT-TPC) inside the SOLARIS solenoid. This experiment is the first attempt at coupling the AT-TPC with SOLARIS to perform a high luminosity transfer reaction measurement without compromising excitation energy and scattering angle resolutions. The angular momentum transfer for states up to $3.40\,\MeV$ are determined from distorted-wave Born approximation analysis of the measured angular distributions, from which the corresponding spectroscopic factors are deduced. These factors are compared with those from various shell model interactions, and those for the $3.40\,\MeV$ state are consistent with a positive parity assignment. Recent \textit{ab initio} no-core configuration interaction (NCCI) calculations with various nucleon-nucleon interactions are presented for the low-lying positive parity states of $^{11}$Be. The excitation energies produced using the Daejeon16 interaction are in good agreement with those found from both this experiment and the literature, thus supporting a positive parity assignment. The $3.40\,\MeV$ state, if assigned a tentative $J^\pi=3/2^+$, would then correspond to the second excited state of the $K^P=1/2^+$ one-neutron halo ground state rotational band also predicted from such NCCI calculations.

The STAR experiment at the Relativistic Heavy Ion Collider presents measurements of correlations between charged hadron triggers of high transverse momenta ($7 < p_{\rm T} < 30$ GeV/$c$) with recoiling charged hadrons ($3 < p_{\rm T} < 7$ GeV/$c$) or charged--particle jets ($p_{\rm T, jet} > 8$ GeV/$c$) in event--activity selected O+O collisions at $\sqrt{s_{\mathrm {NN}}}=200$ GeV. Yields of associated hadrons and jets, normalized by the number of trigger hadrons, are suppressed by approximately 20\% in high event activity relative to low event activity collisions, with an absence of suppression excluded with high significance. This suppression corresponds to a shift in p_{\rm T} of $0.70\pm0.15~(\rm stat.)~\pm0.10~(\rm syst.)$ GeV/$c$ for large--radius charged--particle jets ($R=0.5$), quantifying their energy redistribution due to final--state interactions. These measurements provide strong evidence for jet quenching in O+O collisions at $\sqrt{s_\mathrm{NN}}=200$ GeV, offering new insight into quark--gluon plasma formation in small collision systems.

The precise determination of the parton distribution functions (PDFs) of the proton is an essential ingredient for LHC analyses, including for those at the upcoming High-Luminosity LHC. So far, PDFs are determined from global fits to binned low-dimensional data obtained from unfolded hard-scattering cross section measurements. In this work we demonstrate for the first time the feasibility of neural simulation-based inference (NSBI) for constraining the proton PDFs using a high-dimensional unbinned data set. Exploiting the full statistical power of unbinned data removes the loss of information inherited by the binning procedure. As a proof-of-concept, we determine the gluon PDF from simulated data of top quark pair production at the LHC with $\sqrt{s}=13$ TeV. Taking into account both experimental and theoretical systematic uncertainties in the detector-level features, we demonstrate how the NSBI pipeline achieves significant improvements in precision compared to existing low-dimensional binned analyses. Our results illustrate the potential of unbinned inference to reduce the reliance on coarse approximations of uncertainties and their correlations entering PDF determinations, hence contributing to a new paradigm of unbinned detector-level ML-assisted measurements at the LHC.

The BM@N experiment (Baryonic Matter at the Nuclotron) is the first fixed-target experiment at the JINR NICA accelerator complex. In this work, data on the interactions of a carbon-ion beam with kinetic energies of 4.0A~GeV and 4.5A~GeV with C, Al, Cu, and Pb targets are used to measure transverse momentum spectra and rapidity distributions of $\Lambda$ hyperon yields. The results are compared with the predictions of DCM-SMM, UrQMD, and PHSD transport models and with the $\Lambda$ yield measurements in other experiments at similar collision energies.

The study of spin polarization of $\Lambda$ hyperons in ultrarelativistic heavy-ion collisions provides insights into the angular momentum and vortical structure of the possible existence of QGP. The present study examines the global spin polarization of $\Lambda$ hyperons using a second-order relativistic viscous hydrodynamic framework that incorporates medium vorticity, shear viscosity, and evolving magnetic fields. It explores thermal vorticity evolution in relativistic heavy-ion collisions and evaluates its value at the decoupling isothermal freeze-out surface. We quantify the contributions of thermal vorticity and magnetic field to the global spin polarization of $\Lambda$ hyperons. Comparing results with recent ALICE measurements in Pb+Pb collisions at $\sqrt{s_{NN}}$ = 2.76 and 5.02 TeV shows qualitative agreement, offering new insights into the vortical structure of QCD matter. It also explores the relationship between magnetic and rotational dynamics, with implications for spin polarization at RHIC and LHC energies.

The interaction of neutrons and nuclei at low energies may potentially lead to scattering lengths several orders of magnitude larger than the effective range of the interaction, well beyond the nuclear scale. If such cases existed, they could lead to the observation of the Efimov effect in nuclei, a remarkable universal phenomenon that has been observed only in atoms. The interaction parameters of neutrons scattering off unstable nuclei can be explored in neutron-nucleus systems created after the fast removal of a few nucleons from a slightly heavier beam. The case of the $^{17}$B-$n$ system is considered, and the implications of its potentially huge scattering length on the structure of $^{19}$B as a $^{17}$B-$n$-$n$ Efimov trimer are discussed.

We examine the leading-power fragmentation of fully heavy pentaquarks in high-energy hadronic collisions. To this end, we complete the release of the hadron-structure-oriented PQ5Q1.0 fragmentation functions, by discussing the $P_{5c}$ set and delivering the $P_{5b}$ one. These functions incorporate an improved computation of the initial-scale input for the constituent heavy-quark fragmentation channel, making them particularly suitable for describing both the direct formation of a compact multicharm state and the hadronization from a diquark-antiquark-diquark configuration. For phenomenological applications, we employ the data-validated (sym)JETHAD framework to compute and analyze NLL/NLO$^+$ semi-inclusive production rates of pentaquark-plus-jet systems at the upcoming HL-LHC and the future FCC. This study marks a further step toward connecting hadronic structure, precision QCD, and the emerging physics of exotic matter.

We present an extraction of unpolarized quark transverse-momentum-dependent parton distribution functions (TMD PDFs) from Drell-Yan data within a Bayesian inference framework, incorporating artificial intelligence at multiple stages of the analysis. Our analysis is performed at ${\rm N^3LO}$ in perturbative QCD combined with ${\rm N^4LL}$ resummation accuracy. We first employ an AI-driven iterative procedure to explore and rank candidate functional forms for the nonperturbative contributions to TMD PDFs at the initial scale, as well as for the Collins-Soper evolution kernel, using $\chi^2$ fits and physics constraints. To enable efficient Bayesian inference, we construct a surrogate model for TMD cross sections by training a machine-learning emulator over the parameter space, replacing computationally expensive repeated evaluations and allowing scalable sampling with an affine-invariant Markov Chain Monte Carlo (MCMC) ensemble. Using this framework, we perform a global analysis of Drell-Yan data from fixed-target, RHIC, and LHC experiments and extract TMD PDFs with quantified uncertainties. We compare the results with those obtained using the replica method and highlight differences in the resulting uncertainty estimates.

Nuclear isomers can have significant impacts on astrophysical nucleosynthesis processes, with recent efforts demonstrating that the population of isomeric states with different half-lives may require separate treatment in reaction networks to accurately capture the differences in heating or in identifiable electromagnetic signals. Several potential so-called ``astromers'' in tin and antimony isotopes near doubly-magic $^{132}$Sn were identified and direct mass measurements of their ground and isomeric states were performed with the Canadian Penning Trap at Argonne National Laboratory's CARIBU facility, and their impact on astrophysical reaction rates and in reaction networks calculated. It was found that $^{129g,m}$Sn, with measured mass excesses of $-80 593.2(25)$ keV and $-80 557.4(25)$ keV, respectively, and an excitation energy of $35.8(35)$ keV, behaves as an astromer during neutron capture in the $i$-process and in the $r$-process.

Theoretical considerations predict a specific hierarchy among ratios of net-baryon number cumulants ($\chi_n$, where $n$ is the order of cumulant) in the vicinity of the transition from the low-temperature hadronic phase to the high temperature quark-gluon plasma phase at small baryon chemical potential, $\mu_\mathrm{B}$, in the QCD phase diagram. This hierarchy, $\frac{\chi_6}{\chi_2} < \frac{\chi_5}{\chi_1} < \frac{\chi_4}{\chi_2} < \frac{\chi_3}{\chi_1}$, has been observed by the STAR experiment in net-proton number (a proxy of net-baryon number) cumulant ratios over a broad range of collision energies. Motivated by these findings, we investigate whether similar ordering emerges generically in finite statistical systems undergoing second-order phase transitions. We employ two different spin models: the two-state and three-state Potts models in two dimensions, both exhibiting a transition from an ordered phase to a disordered phase at their respective critical temperatures. Monte Carlo simulations are performed on square lattices of varying sizes using the Wolff cluster algorithm. Cumulants of the total magnetization are calculated up to sixth order in both of these models in a temperature range near their corresponding critical temperatures. Higher-order cumulants exhibit extrema (peaks/troughs) whose magnitudes grow with both cumulant order and lattice size, reflecting enhanced critical fluctuations. Except within a narrow temperature window above the critical temperature, neither the complete hierarchy nor its exact reverse is realized over the studied temperature range in either model.

This work presents a novel cosmic-ray scattering experiment employing a Resistive Plate Chambers (RPC) muon tomography system. By introducing the scattering angle between incident and outgoing cosmic-ray tracks as a key observable, this approach enables simultaneous studies of secondary cosmic-ray composition and searching for new physics. During a 63-day campaign, 1.18 million cosmic ray scattering events were recorded and analyzed. By performing combined template fits to the observed angular distribution, particle abundances are measured -- for example, resolving the electron component at $\sim 2\%$ precision. Furthermore, constraints are established on elastic muon dark matter (DM) scattering cross-sections for muon-philic dark matter. At the $95\%$ confidence level, the limit reaches 1.61 $\times$ $10^{-17}$ $\rm{cm}^{2}$ for 1 GeV slow DM, demonstrating sensitivity limit to light muon-coupled slow DM, in scenarios where a strongly interacting dark matter component is captured and thermalized within the Earth, leading to large surface densities.