In this work, we have calculated the transport coefficients: shear viscosity and thermal conductivity inside the neutron star core. Our calculation is based on the relativistic kinetic theory approach using a modified BUU equation for quasi-particles whose mass and the chemical-potential and thus in turn the Fermi surface varies with the baryonic density $\rho_{B}$ and the temperature of the medium, and we have used the relaxation time approximation. For the description of the hadronic matter inside the neutron star, we consider the relativistic mean field model with three different kinds of parameterizations. We have found that the shear viscosity is predominantly influenced by neutrons, while thermal conductivity is primarily dominated by electrons.

The $p(n,\gamma)$ and $d(p,\gamma)$ reactions are key nuclear inputs for Big Bang nucleosynthesis. In this work, both reactions are analyzed within a consistent two-body potential framework based on the Malfliet-Tjon interaction, including contributions from both $E1$ and $M1$ transitions. A single scaling factor $\lambda$ controlling the low-energy scattering dynamics is constrained by the $p(n,\gamma)$ and propagated consistently to the $d(p,\gamma)$. The obtained abundance, $\mathrm{D/H} = 2.479^{+0.350}_{-0.177}\times 10^{-5}$, is in good agreement with values inferred from metal-poor damped Lyman-$\alpha$ systems. The modest variations of $\lambda$ lead to a significant change in the predicted $\mathrm{D/H}$ ratio and light-element abundances.

Understanding how nuclear size evolves with the number of protons and neutrons tests our models of strongly interacting matter. The nuclear charge (and proton) radii accessible through electromagnetic probes carry fundamental information on the saturation density and nuclear correlations. The radii of the neutron distribution are more difficult to measure, but they are important for our understanding of the isovector properties of nuclei that depend on the proton-to-neutron asymmetry, and on extended nucleonic matter in neutron stars. Interaction cross sections offer one of the few direct experimental windows into the neutron radii of nuclei far from stability, but translating these measurements into reliable structural information requires an integrated theoretical framework that links structure and reactions with a rigorous treatment of uncertainty. In this work, we compute interaction cross sections by using uncertainty-quantified proton and neutron distributions obtained in the self-consistent nuclear Density Functional Theory (DFT) with the Fayans energy density functional. The resulting densities are used in a modernized Glauber reaction framework, which features the refit of nucleon-nucleon profile functions. Applying this pipeline to the existing data on the calcium isotopic chain, we find no evidence for the dramatic neutron swelling reported earlier. While focusing here on the Ca chain, the methodology proposed in this work is applicable to interaction cross section measurements across the nuclear chart and is well-suited for new experiments currently planned at leading rare isotope facilities.

Binary neutron star mergers and proto-neutron stars provide unique environments where dense matter is hot, lepton rich, and potentially undergoes a transition from hadronic to deconfined quark matter. We investigate the thermodynamics and stellar properties of hybrid matter under such conditions. The hadronic phase is described within a covariant density functional framework, while the quark phase is modeled using a Nambu-Jona-Lasinio (NJL) model that includes repulsive vector interactions, the axial $U_A(1)$-breaking 't Hooft determinant interaction, and two-flavor color-superconducting (2SC) pairing. The phase transition between hadronic and quark matter is constructed using a mixed-phase prescription that enforces baryon and lepton number conservation, allowing us to follow thermodynamic trajectories at fixed entropy per baryon and fixed lepton fraction. We analyze the phase structure of dense matter at finite temperature and study the composition of the hadronic, mixed, and quark phases in both neutrino-trapped and neutrino-free regimes. Our results show that neutrino trapping significantly modifies the particle composition and shifts the onset of deconfinement to higher densities. Using the resulting equations of state, we compute static stellar configurations and examine the influence of temperature and lepton content on the mass-radius relation of hybrid stars. Hot, neutrino-rich configurations are found to have larger radii and slightly higher maximum masses than their cold counterparts.

States in the neutron-rich isotope 51 Ca were populated via the 50 Ca(d, p) transfer reaction in inverse kinematics at a beam energy of about 14 AMeV. The experiment was performed using a decelerated radioactive 50 Ca beam from the OEDO facility and the TiNA2 silicon array in combination with the SHARAQ magnetic spectrometer at RIBF/RIKEN. The energies of excited states in 51 Ca were reconstructed via missing mass spectroscopy, and angular distributions of protons were measured to extract differential cross sections. From a comparison with adiabatic distorted wave approximation (ADWA) calculations, spectroscopic factors were deduced for several states, including the ground state and excited states up to 4.2 MeV. These results are compared with shell-model calculations, as well as ab initio valence-space in-medium similarity renormalization group (VS-IMSRG) predictions. The data support the assignment of the 1/2- and 5/2- single-particle states and provide evidence for a candidate 9/2+ state with a structure consistent with neutron excitation into the 0g9/2 orbital. These findings contribute new constraints on the single-particle structure and shell evolution in neutron-rich calcium isotopes.

The color-octet (CO) mechanism is a cornerstone of non-relativistic QCD, yet its long-distance matrix elements remain limited, preventing stringent tests of the theory. We demonstrate that the Artru-Collins asymmetry in hadronic decays of the $P$-wave bottomonium state $\chi_{b2}$ provides a direct probe of CO dynamics. The asymmetry arises exclusively from the CO decay channel, whereas the color-singlet (CS) contribution affects only the unpolarized rate, so that a nonzero signal constitutes unambiguous evidence of the CO mechanism. This observable provides a novel way to extract the ratio $\rho_8$ between CO and CS matrix elements. Focusing on $e^+e^-\to\Upsilon(2S)\to\gamma\,\chi_{b2}$ at Belle, we show that the asymmetric beam configuration preserves the asymmetry in the laboratory frame and avoids the strong suppression present in the center-of-mass frame. With the Belle II dataset, $\rho_8$ could be determined with sufficient precision to address the long-standing discrepancy between the lattice calculations and phenomenological determinations.

In this talk, we present novel methods to investigate light-quark dipole interactions at colliders. Our approach includes: (1) measuring azimuthal asymmetries of a collinear dihadron in semi-inclusive deep inelastic lepton scattering off an unpolarized proton target at the Electron-Ion Collider, and (2) utilizing azimuthal asymmetries of dihadron $(h_1 h_2)$ produced in association with an additional hadron $h^\prime$ at lepton colliders. These asymmetries provide a unique means to observe transversely polarized quarks, which arise from quantum interference and are exclusively sensitive to dipole interactions at the leading power of the new physics scale. Consequently, they exhibit a linear dependence on the dipole couplings, free from contamination by other new physics effects. This approach has the potential to significantly strengthen current constraints by one to two orders of magnitude. By combining all possible channels of $h^\prime$, this novel approach enables the disentanglement of the up- and down-quark dipole moments. Additionally, by controlling the electron's longitudinal polarization and the center-of-mass energy, it separates the contributions mediated by photon and weak boson. Furthermore, it allows for a simultaneous determination of both real and imaginary parts of the dipole couplings, offering a new avenue for investigating potential $CP$-violating effects at high energies.

A key question about the QCD phase diagram is whether there is a critical point somewhere on the boundary between the hadronic and quark-gluon plasma phases, and if so where. Heavy-ion collisions offer a unique opportunity to search for signatures of such a critical point by analyzing event-by-event fluctuations in particle multiplicities. To draw meaningful conclusions from experimental data, a theoretical framework is needed to link QCD thermodynamics with the particle spectra and correlations observed in detectors. The Equation of State (EoS) of QCD near a critical point can be related to the universal Gibbs free energy of the 3D Ising model using four currently unknown non-universal mapping parameters whose values are determined by the microscopic details of QCD. We utilize the maximum entropy approach to freeze-out the fluctuations in order to make estimates for factorial cumulants of proton multiplicities, assuming thermal equilibrium, for a family of EoS with a 3D Ising-like critical point, varying the microscopic inputs that determine the strength and structure of the critical features. We quantify the effect of the non-universal mapping parameters, and the distance between the critical point and the freeze-out curve, on the factorial cumulants of proton multiplicities.

A modern chiral potential incorporating the three-body force is adopted to investigate bulk properties, spectra, and nuclear responses of closed-(sub)shell nuclei throughout the nuclear chart within a particle-hole (p-h) renormalized random-phase approximation (RRPA) scheme using a Hartree- Fock (HF) single-particle basis. Our analysis shows that all instabilities induced by the quasiboson approximation (QBA) underlying RPA are removed and an overall better consistency with the experiments is achieved for all observables of the investigated nuclei. The residual discrepancies point out the need of going beyond the p-h space.

We study how the inclusion of energy dependence as dictated by quantum chromodynamic (QCD) small-$x$ evolution equations affects key observables in ultra-relativistic heavy-ion collisions. Specifically, we incorporate JIMWLK evolution into the IP-Glasma framework, which serves as the initial condition for a simulation pipeline that includes viscous relativistic hydrodynamics and a hadronic afterburner. This approach enables a consistent modeling of highly energetic nuclei across varying Bjorken-$x$ values, which are relevant for different collision energies and rapidity regions. In comparison to the standard IP-Glasma setup without small-$x$ evolution, we observe pronounced changes in particle multiplicities and spectral distributions, especially in smaller systems and at the highest available energies. We further explore effects on anisotropic flow observables and correlations between mean transverse momentum and elliptic flow. Our findings underscore the critical role of nonlinear QCD evolution in accurately modeling the early stages of heavy-ion collisions, as well as its implications for extracting transport properties of the quark-gluon plasma.

We analyze the elastic $\alpha$-$^{12}$C scattering including the contribution of resonance states below the $p$-$^{15}$N breakup threshold energy. We use the cluster effective field theory in which scattering amplitude is expanded in terms of the effective range expansion parameters for the angular momentum states from $l=0$ to $l=6$. The amplitude contains 37 parameters, which are determined by fitting to 11~392 differential cross section data points of the elastic $\alpha$-$^{12}$C scattering. To optimize the fitting process, we implement the differential evolution (DE) algorithm, which performs a global search over the high-dimensional parameter space and consistently converges to the same minimum $\chi^{2}$ value across independent runs, suggesting proximity to the global minimum within the explored domain. In parallel, the Markov chain Monte Carlo (MCMC) method is used to crosscheck the DE results and to estimate the parameter uncertainties. The best fit yields $\chi^{2}/N\!\simeq\!6.2$ for the elastic scattering data. Using the determined 37 parameters, we calculate the differential cross sections and the phase shifts of the elastic $\alpha$-$^{12}$C scattering and compare the results with experimental data and those of an $R$-matrix analysis. Our result of the cross section agrees with the experimental data as accurately as an $R$-matrix analysis. The results demonstrate that the cluster effective field theory, combined with global optimization and uncertainty quantification based on DE-MCMC methods, provides a reliable and systematic framework for applications to low energy phenomena relevant to stellar evolution and nucleosynthesis.

The observation of neutron star mergers with gravitational waves (GWs) has provided a new method to constrain the dense-matter equation of state (EOS) and to better understand its nuclear physics. However, inferring nuclear microphysics from GW observations necessitates the sampling of EOS model parameters that serve as input for each EOS used during the GW data analysis. The sampling of the EOS parameters requires solving the Tolman-Oppenheimer-Volkoff (TOV) equations a large number of times -- a process that slows down each likelihood evaluation in the analysis on the order of a few seconds. Here, we employ emulators for the TOV equations built using multilayer perceptron neural networks to enable direct inference of nuclear EOS parameters from GW strain data. Our emulators allow us to rapidly solve the TOV equations, taking in EOS parameters and outputting the associated tidal deformability of a neutron star in only a few tens of milliseconds. We implement these emulators in \texttt{PyCBC} to directly infer the EOS parameters using the event GW170817, providing posteriors on these parameters informed solely by GWs. We benchmark these runs against analyses performed using the full TOV solver and find that the emulators achieve speed ups of nearly \emph{two orders of magnitude}, with negligible differences in the recovered posteriors. Additionally, we constrain the slope and curvature of the symmetry energy at the 90\% upper credible interval to be $L_{\rm sym}\lesssim106$ MeV and $K_{\rm sym}\lesssim26$ MeV.

We have studied how the transport of charge and heat as well as associated observables become influenced by a weak-momentum anisotropy arising due to the asymptotic expansion of baryon asymmetric matter in the initial stages of heavy ion collisions. This study facilitates the understanding of the local equilibrium property of the medium through the Knudsen number, and explores the correlation between the heat flow and the charge flow through the Lorenz number in the Wiedemann-Franz law for an anisotropic hot QCD medium at finite baryon asymmetry. We have determined the electrical and the thermal conductivities by solving the relativistic Boltzmann transport equation in the relaxation time approximation within the kinetic theory approach. The interactions among partons are appended through their distribution functions within the quasiparticle model of the hot QCD medium at finite temperature, anisotropy and baryon asymmetry. We have observed a decrease in both electrical and thermal conductivities in the presence of expansion-induced anisotropy for baryonless scenario as well as for baryon asymmetric scenario. Conversely, these conductivities are found to be larger in the baryon asymmetric matter as compared to their counterparts in the baryonless matter. The impact of anisotropy on the baryon asymmetric matter is as conspicuous as on the baryonless matter. The above results are attributed to the squeezing of the distribution function due to the momentum anisotropy generated by the asymptotic expansion of baryon asymmetric matter and the dispersion relations of partons in the presence of anisotropy. Additionally, the aforesaid observables are also modulated by the expansion-induced anisotropy in the baryon asymmetric medium, indicating new predictions for the equilibrium characteristic and the relative behavior between the heat and charge flow for the said medium.