We analyze the deuteron charge and quadrupole form factors using the latest NN potentials and charge-density operators derived within chiral effective field theory. We derive relations between 1N,2N charge densities and nucleon form factors and employ several recent empirical parametrizations for proton and neutron form factors. We fit low-energy constants appearing in the fifth-order 2N...
LA-UR-21-25112 - Neutron stars contain the largest reservoirs of degenerate fermions, reaching the highest densities we can observe in the cosmos, and probe matter under conditions that cannot be recreated in terrestrial experiments. Throughout the Universe, a large number of high-energy, cataclysmic astrophysical collisions of neutron stars are continuously occurring. These collisions provide...
The nuclear symmetry energy and its slope $L$ are fundamental quantities describing the properties of dense matter around nuclear saturation.
New measurements of the neutron-skin thickness of $^{208}\rm Pb$ have sparked recent interest in constraints on the slope of the symmetry energy, $L$, some of which can also be inferred from astrophysical systems, such as neutron star mergers.
In...
The low-energy QCD, the theory describing the strong interaction, is still missing fundamental experimental results in order to achieve a breakthrough in its understanding. Among these experimental results, the low-energy kaon-nucleon/nuclei interaction studies are playing a key-role, with important consequences going from particle and nuclear physics to astrophysics.
Combining the excellent...
Binary Neutron Star (BNS) mergers provide a rich laboratory for the study of matter at extreme densities and temperatures. In this talk we present the results of state-of-the-art BNS simulations using modern 3-parameter (density, temperature, electron fraction) equations of state (EoSs), with particular focus on behaviour due to temperature and composition dependant effects.
First, we go...
During the late stages of a neutron star binary inspiral finite-size effects come into play, with the tidal deformability of the supranuclear density matter leaving an imprint on the gravitational-wave signal. As demonstrated in the case of GW170817—the first direct detection of gravitational waves from a neutron star binary—this can lead to strong constraints on the neutron star equation of...
In this work, we focus on identifying which conditions generate massive stars and how these affect the radii and tidal deformability of intermediate and massive stars. We build equations of state either from realistic models with exotic degrees of freedom or in a model-independent approach, using a functional form of the speed of sound and discuss cross-overs, first-order phase transitions,...
In this talk I will revisit modified and direct Urca
processes in nuclear matter under conditions that we expect in neutron
star mergers. Nuclear Urca processes have shown to be a potential
significant source of bulk viscosity under merger conditions. I will
explain how a correct relativistic treatment can alter the rates and
the true beta equilibrium significantly, and present a new way...
We present the results concerning analytic (3+1)-dimensional inhomogeneous and topologically nontrivial pion systems hosting topologically stable baryons. This phase, relevant for the core of compact stars featuring a pion condensed core, is discussed within two-flavor leading order chiral perturbation theory.
Within General Relativity there is a maximum latent heat for a first order phase transition that a neutron star can support, the Seidov limit. If neutron-star matter exceeds it, the transition to the presumed exotic phase will not be complete before the star undergoes gravitational collapse.
However, this limit should generally be different in theories of modified gravity, that are to be...
Holographic techniques are particularly fit to analyzing matter at extreme conditions where QCD matter is strongly coupled. Combining predictions of the holographic model with state-of-the-art effective field theory models of nuclear matter, I construct a family of feasible "hybrid" equations of state which cover both the quark matter and nuclear matter phases. The model predicts, among other...
In this talk, we study a bottom-up holographic model where nuclear matter is realized as a dilute gas of deformed instantons in six dimensions. In the probe approximation, we obtain a stiff equation of state for the nuclear matter, where the speed of sound is relatively large. Based on the above observation, Tolman-Oppenheimer-Volkov (TOV) equation is solved numerically and then we find the...
We present the unified equation of state with induced surface tension (IST) that reproduces the nuclear matter properties, fulfills the proton flow constraint, provides a high-quality description of hadron multiplicities created during the nuclear-nuclear collision experiments, and is equally consistent with NS observations. Obtained tidal Love numbers are in full agreement with the...
I present the results of a systematic investigation of the possible locations for the neutron star special point (SP), a unique feature of hybrid neutron stars in the mass-radius. The study is performed within the two-phase approach where the high-density (quark matter) phase is described by the constant-sound-speed (CSS) equation of state (EoS) and the nuclear matter phase around saturation...
Taking into account experimental data, theoretical calculations and neutron star observations to constrain the equation of state several properties of neutron stars will be discussed, in particular: possible properties of hybrid stars, the influence of hyperonic degrees of freedom on the cooling of neutron stars, the presence of light clusters in the warm equation of state and the effect of...
I will discuss the properties of some spatially inhomogeneous phases in hadronic matter at finite densities
Chiral perturbation theory is a low-energy effective theory for QCD that gives
model-independent prediction in its region of validity. In this talk, I will present recent progress in two and three-flavor chpt at finite isospin density.
This is includes thermodynamic quantities, quark, and pion condensates, and phase diagrams, all calculated at next-to-leading order. The results are compared...
We point out a novel configurations in holographic QCD, allowing baryons to coexist with fundamental quarks. The resulting phase is a dual realization of quarkyonic matter, which is predicted to occur in QCD at a large number of colors, and possibly plays a role in real-world QCD as well. We find that holographic quarkyonic matter is chirally symmetric and that, for large baryon chemical...
Strong magnetic fields are relevant for both systems where QCD matter can be studied in practice - heavy ion collisions and neutron stars. The ground state of QCD at zero temperature, in sufficiently strong magnetic fields and at moderate baryon densities was recently shown to carry a crystalline condensate of neutral pions: the chiral soliton lattice. This phase of matter might be relevant...
A principal element of unified description of strongly interacting matter within the effective theories corresponds to hadronization of chiral quark models and incorporation of the confinement mechanism into them, manifesting the switching between hadron and quark degrees of freedom. Such an approach is formulated based on a relativistic density-functional motivated by the string-flip model....
