The ultra-soft narrow-line Seyfert 1 galaxy 1H 0707−495 is a well-known and highly variable active galactic nucleus (AGN), with acomplex, steep X-ray spectrum, and has been studied extensively with XMM-Newton. 1H 0707−495 was observed with the extendedROentgen Survey with an Imaging Telescope Array (eROSITA) aboard the Spectrum-Roentgen-Gamma (SRG) mission on October11, 2019, for about 60,000...
We study the neutrino chirality flip during the birth of a neutron star, produced in a core made of strange quark matter. This mechanism is applied to the neutron star kick velocity problem and we show that it is efficient when the neutrino magnetic moment is not smaller than $4.7 \times 10^{-15}\mu_B$, where $\mu_B$ is the Bohr magneton. When this lower bound is combined with the most...
We study the quantum magnetic collapse of a partially bosonized npe-gas and obtain that this type of collapse might be one of the mechanisms behind matter expulsion out of compact objects. We check also that this gas might form a stable stream of matter whose collimation is due to its strong self-generated magnetic field. Possible astrophysical applications of these results, in particular...
We study the thermodynamic properties of a magnetized neutral vector boson gas at any temperature, with the aim to provide equations of state that allow more general and precise descriptions of astrophysical phenomena. The all-temperature analytical expressions for the thermodynamic magnitudes, as well as their non-relativistic limits, are obtained starting from the energy spectrum given by...
We study stable spheroidal configurations of magnetized strange stars using an axially symmetric metric in spherical coordinates that uses a gamma parameter to link the anisotropy in the equation of state due to the magnetic field with the deformation of the star. The stars are composed by magnetized Strange Quark Matter described within the framework of the MIT-bag model. Their masses, radii,...
The quark-gluon plasma (QGP) is intensively studied since decades in Heavy-Ion Collisions (HICs) at high energy and recently also in high-multiplicity events of relativistic proton-nucleus collisions. Both collision systems are characterized by the presence of very intense electromagnetic fields, which attain their maximal strength in the early stage and interplay with the strong vorticity...
The study of hypernuclei and their production mechanisms open new opportunities for nuclear/particle physics and astrophysics. The hyperons influence many nuclear properties in finite nuclei and in neutron stars (infinite nuclear matter). We review the main processes leading to the production of hypernuclei in nuclear reactions including relativistic ion collisions. Such deep-inelastic...
We explore the rapidity and transverse momentum dependence and mass number scaling of collective flow harmonics of light nuclei in Au + Au reactions at a beam energy of 1.23 AGeV within the UrQMD approach. These investigations are of direct relevance for the high acceptance di electron spectrometer (HADES) experiment at the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt, Germany,...
The deuteron coalescence parameter $B_2$ in proton+proton and nucleus+nucleus collisions in the energy range of $\sqrt{s_{NN}}=$ 900 - 7000 GeV for proton+proton and $\sqrt{s_{NN}}=$ 2 - 2760 GeV for nucleus+nucleus collisions is analyzed with the Ultrarelativistic Quantum Molecular Dynamics (UrQMD) transport model, supplemented by an event-by-event phase space coalescence model for deuteron...
The hadronic transport simulation UrQMD is used to pin down the chemical freeze-out space-time point of each final state pion. In combination with a coarse-grained collision evolution, the local temperature $T$ and the local baryo-chemical potential $\mu_{\rm B}$ are estimated up to the top RHIC energies. The results match thermal model estimates of experimental data with high accuracy....
In this presentation I will motivate and construct the hydrodynamic description of a chiral plasma subject to a strong magnetic field. Such a description can be applied to the quark gluon plasma or astrophysical plasma. Kubo formulae are computed which relate 22 transport coefficients to particular correlation functions. Among those transport coefficients, 8 are novel. Known transport...
Quantum vacuum in large fields of the order of twice or greater than the critical Schwinger field 2Bc shows strong anisotropic properties: virtual photons as well as electrons and positrons tend to propagate in a parallel direction to the magnetic field. In order to overcome this anisotropic behavior, we propose an heuristic model based on fermion pairing of boson‐vacuum in the form of...
We calculate the time delay for photons propagating both in QED vacuum and in a charged electron-positron gas, in an external magnetic field. Our final aim is the study of this effect for photons in a neutron star magnetosphere like scenario.
An analysis is realized on the stability of the recently proposed static solutions of Boson Stars. These solutions of Einstein-Klein-Gordon (EKG) equations arise from considering the interactions of a real scalar field with matter. We assumed that the inclusion of the scalar field in addition with matter, allows to justify that stability implies the total mass of the solution should grow when...
We discuss about formation of deuterons in hadronic matter by means of a microscopic description of inelastic many-body scattering processes. The dominant reactions $dN \leftrightarrow NNN$ and $d\pi \leftrightarrow NN\pi$ which are characterized by measured cross sections $\sigma \simeq 200 \, mb$, much larger than subdominant $d\pi \leftrightarrow NN$ process, have been fully implemented...
Flow coefficients $v_{n}$ of the orders $n = 1 - 6$ are measured with the High-Acceptance DiElectron Spectrometer (HADES) at GSI for protons, deuterons and tritons in Au+Au collisions at $\sqrt{s_{NN}} = 2.4$ GeV.
HADES provides a large acceptance combined with a high mass-resolution and therefore allows to study dielectron, hadron and light nuclei production in heavy-ion collisions with...
Holography, also known as AdS/CFT correspondence, lies at the intersection of gravitational physics and quantum field theory. It is a duality which maps the physics of a strongly coupled quantum field configuration onto the physics of a weakly curved model spacetime. It has been successfully applied to describe a variety of systems in gravitational terms–from condensed matter to quantum...
We study the influence of the baryon chemical potential μB on the dynamical properties of the Quark–Gluon–Plasma (QGP) in- and out-of equilibrium. The description of the QGP in equilibrium is based on the effective propagators and couplings from the Dynamical QuasiParticle Model (DQPM)that is matched to reproduce the equation-of-state of the partonic system above the deconfinement temperature...
Two of the most important observables for understanding Quark-Gluon Plasma (QGP) physics are quarkonia suppression and the energy loss process. Although quarkonia are compound objects, it is usually advocated that their production at intermediate 𝑝T follows a behavior similar to the one of single particles, like for instance D mesons. Ultimately, this kind of study will bring more information...
