Conditions are found, at which in the nuclear matter there may appear a spatially nonuniform $p$ wave $\pi^0$ condensate supplemented by a spatially varying spontaneous magnetization. The pion-nucleon interaction and the anomaly contributions to the magnetization are taken into account. Response of the system on the external magnetic field is also considered. Then the model of nonoverlapped nucleon Fermi spheres is employed. Arguments are given in favor of the possibility of the occurrence of the $\pi^0$-condensation and a spatially varying magnetization as well as effects of pronounced anisotropic pion fluctuations at finite pion momentum in peripheral heavy-ion collisions. Relevant effects such as response on the rotation, charged pion condensation and other are discussed.
We study the equation of state of hot and dense hadronic matter using an extended Chiral Mean Field (CMF) model framework where the addition is the inclusion of interactions of thermally excited mesons. This is implemented by calculating the in-medium masses of pseudoscalar and vector mesons, obtained through the explicit chiral symmetry-breaking and vector interaction terms in the Lagrangian, respectively, prior to applying the mean-field approximation. As a result, the in-medium meson contributions generate a feedback term to the CMF's equations of motion, which then modifies the equation of state. With this improvement, we quantify the effect on the equation of state of strongly interacting matter through comparisons with state-of-the-art lattice QCD results and other hadronic models like the Hadron Resonance Gas model. We find that the results of the updated hadronic CMF model with an improved meson description (mCMF) provide a better agreement with lattice-QCD data for thermodynamic state variables across a wide range of temperatures and baryon chemical potentials.
Exploration of the QCD phase diagram is pivotal in particle and nuclear physics. We construct a full four-dimensional equation of state of QCD with net baryon, electric charge, and strangeness by extending the NEOS model beyond the conventional two-dimensional approximation. Lattice QCD calculations based on the Taylor expansion method and the hadron resonance gas model are considered for the construction. We also develop an efficient numerical method for applying the four-dimensional equation of state to relativistic hydrodynamic simulations, which can be used for the analysis of nuclear collisions at beam energy scan energies and for different nuclear species at the BNL Relativistic Heavy Ion Collider.
We determine the form of dissipative currents at the first order in relativistic spin hydrodynamics with finite chemical potential including gradients of the spin potential. Taking advantage of isotropy in the hydrodynamic local rest frame, using a suitable matching condition for the flow velocity and enforcing the semi-positivity of entropy production, we find 23 dissipative transport coefficients relating dissipative currents to gradients of the thermo-hydrodynamic fields: 4 for the symmetric part of the energy-momentum tensor, 5 for the antisymmetric part, 3 for the conserved vector current, and 11 for the spin tensor. We compare our finding with previous results in literature.
The relativistic viscous hydrodynamic description of the quark-gluon plasma by M\"uller-Israel-Stewart formulations has been very successful, but despite this success, these theories present limitations regarding well-posedness and causality. In recent years, a well-behaved version of the relativistic Navier-Stokes equations has been formulated, appearing as a promising alternative in which those limitations are absent. Using this novel theory, we perform numerical simulations of a quark-gluon plasma fluid that we use to describe experimental data on the transverse momentum distribution of hadrons from central Pb-Pb collisions measured at the LHC.
In quantum computing, non-stabilizerness -- the magic -- refers to the computational advantage of certain quantum states over classical computers and is an essential ingredient for universal quantum computation. Employing the second order stabilizer R\'enyi entropy to quantify magic, we study the production of magic states in Quantum Electrodynamics (QED) via 2-to-2 scattering processes involving electrons and muons. Considering all 60 stabilizer initial states, which have zero magic, the angular dependence of magic produced in the final states is governed by only a few patterns, both in the non-relativistic and the ultra-relativistic limits. Some processes, such as the low-energy $e^-\mu^-\to e^-\mu^-$ and Bhabha scattering $e^-e^+\to e^-e^+$, do not generate magic at all. In most cases the largest magic generated is significantly less than the maximal possible value of $\log (16/7) \approx 0.827$. The only instance where QED is able to generate maximal magic is the low-energy $\mu^-\mu^+\to e^-e^+$, in the limit $m_e/m_\mu \to 0$, which is well approximated in nature. Our results suggest QED, although capable of producing maximally entangled states easily, may not be an efficient mechanism for generating quantum advantages.
Using a holographic prescription for the Schwinger-Keldysh closed time path, we derive the effective action for a dissipative neutral fluid holographically described by the Einstein gravity in an asymptotic AdS spacetime. In the saddle point approximation for the dual gravity, the goal is achieved by solving the double Dirichlet problem for the linearized gravitational field living in a complexified static AdS black brane background. We adopt a partially on-shell scheme for solving the bulk dynamics, which is equivalent to ``integrating out'' the gapped modes in the boundary field theory. The boundary effective action in the fluid spacetime, identified as the partially on-shell bulk action, is computed to first order in boundary derivative and to cubic order in AdS boundary data. The boundary effective action, rewritten in the physical spacetime, successfully reproduces various results known in the framework of classical hydrodynamics, confirming our holographic derivation.