Phase Transitions In Matter Research Articles

Exploring nuclear matter phase transition through $$p_T$$ spectra analysis using blast wave model with Tsallis statistics in proton–proton collisions

Exploring nuclear matter phase transition through $$p_T$$ spectra analysis using blast wave model with Tsallis statistics in proton–proton collisions

Deconfinement and chiral phase transitions in quark matter with chiral imbalance

We study the thermodynamics of the Polyakov-Nambu-Jona-Lasinio model considering the effects of an effective chiral chemical potential. We offer a new parametrization of the Polyakov-loop potential depending on temperature and the chiral chemical potential which, when used together with a proper regularization scheme of vacuum contributions, predicts results consistent with those from lattice simulations. Published by the American Physical Society 2024

Holographic entanglement properties in the QCD phase diagram from Einstein-Maxwell-dilaton models

In this study, we investigate the behavior of entanglement properties in the QCD phase diagram using holographic Einstein-Maxwell-dilaton models. We consider two representative holographic QCD models and examine various entanglement measures, including entanglement entropy, conditional mutual information, and the entanglement of purification. We find that the entanglement entropy obtained using the direct UV-cutoff renormalization method shows significant dependence on the specific model being used. However, the outcomes of other nondivergent entanglement measures, such as cutoff-independent entanglement entropy, conditional mutual information, and the entanglement of purification, exhibit congruence in our calculations. When we focus specifically on the temperature range below 300 MeV, we observe a similar behavior among the three entanglement measures. This may suggest that within this temperature range, the entanglement of QCD matter decreases with increasing temperature. Additionally, we observe distinct phase transition behaviors of entanglement properties at the critical end point and first-order phase transitions. This observation highlights the potential of entanglement properties as effective order parameters for QCD matter phase transitions. Published by the American Physical Society 2024

Analytic soliton solutions to the shallow water dispersive long gravity wave equations: the first integral approach in nonlinear physics

In this article, we investigate the (2+1)-dimensional dispersive long water wave equation and the (1+1)-dimensional Phi-four equation, which describe the behavior of long gravity waves with small amplitudes, long wave propagation in oceans and seas, coastal structures and harbor design, effects of wave motion on sediment transport, quantum field theory, phase transitions of matter, ferromagnetic systems, liquid-gas transitions, and the structure of optical solitons. We use the first integral technique and obtain new and generic solutions for the models under consideration. By setting definite values for the associated parameters, various types of richly structured solitons are generated. The solitons include kink, flat kink, bell-shaped, anti-bell-shaped, and singular kink formations. These solutions allow for a profound understanding of the behavior and properties of the phenomena, offering new insights and potential applications in the associated field. The first integral technique is simpler, directly integrates the models, and the solutions offer clear insights into the underlying phenomena without requiring intermediate steps, making it widely applicable to various other models, including nonlinear equations and those that are challenging to solve using other standard techniques.

Dark matter phenomenology and phase transition dynamics of the next-to-minimal composite Higgs model with a dilaton

In this paper, we conduct a comprehensive study of the next-to-minimal composite Higgs model (NMCHM) extended with a dilaton field χ (denoted as NMCHMχ). A pseudo-Nambu-Goldstone boson (pNGB) η, resulting from the SO(6)→SO(5) breaking, serves as a dark matter (DM) candidate. The inclusion of the dilaton field is helpful for evading the stringent constraints from dark matter direct detection, as it allows for an accidental cancellation between the amplitudes of DM-nucleon scattering, an outcome of the mixing between the dilaton and Higgs fields. The presence of the dilaton field also enriches the phase transition patterns in the early universe. We identify two types of phase transitions: (i) a 1-step phase transition, where the chiral symmetry and electroweak symmetry breaking (EWSB) occur simultaneously, and (ii) a 2-step phase transition, where the chiral symmetry breaking transition takes place first, followed by a second phase transition corresponding to EWSB. Since the first-order phase transitions can be strong due to supercooling in our model, we also examine the stochastic background of gravitational waves generated by these phase transitions. We find that these gravitational waves hold promise for detection in future space-based gravitational wave experiments, such as LISA, Taiji, BBO, and DECIGO. Published by the American Physical Society 2024

Vortex loop dynamics and dynamical quantum phase transitions in three-dimensional fermion matter

Vortex loop dynamics and dynamical quantum phase transitions in three-dimensional fermion matter

Constraining the Onset Density for the QCD Phase Transition with the Neutrino Signal from Core-collapse Supernovae

The occurrence of a first-order hadron–quark matter phase transition at high baryon densities is investigated in astrophysical simulations of core-collapse supernovae, to decipher yet incompletely understood properties of the dense matter equation of state (EOS) using neutrinos from such cosmic events. It is found that the emission of a nonstandard second neutrino burst, dominated by electron antineutrinos, is not only a measurable signal for the appearance of deconfined quark matter but also reveals information about the state of matter at extreme conditions encountered at the supernova (SN) interior. To this end, a large set of spherically symmetric SN models is investigated, studying the dependence on the EOS and the stellar progenitor. General relativistic neutrino-radiation hydrodynamics is employed featuring three-flavor Boltzmann neutrino transport and a microscopic hadron-quark hybrid matter EOS class. Therefore, the DD2 relativistic mean-field hadronic model is employed, and several variations of it, and the string-flip model for the description of deconfined quark matter. The resulting hybrid model covers a representative range of onset densities for the phase transition and latent heats. This facilitates the direct connection between intrinsic signatures of the neutrino signal and properties of the EOS. In particular, a set of linear relations has been found empirically. These potentially provide a constraint for the onset density of a possible QCD phase transition from the future neutrino observation of the next galactic core-collapse SN, if a millisecond electron anti-neutrino burst is present around or less than 1 s.

PRINCIPLES OF ORGANIZATION OF THE MATERIAL WORLD

An attempt has been made to present and describe the PRINCIPLES OF ORGANIZATION OF THE MATERIAL WORLD using the “Scheme of the structure of our world”, which is the foundation of the philosophy of Hermeticism. In it, the three parts of the philosophy of the Universe are designated as the three Kingdoms that make up our world - Abstractions, Mass and Gravity, as well as Radiation. A diagram is shown for converting time into mass and back to implement phase transitions of matter into various states in the series: radiation – free space – dark matter – baryonic matter – black holes. The Scheme points to the location of dark energy. The geometric body of the rank space and the fractal principle of its construction are demonstrated. The previously proposed concepts were repeated: a) material zero as an elementary/electromagnetic quantum of space EQS; b) space-time complex of STC inside the quantum of space; c) the axis of the speed of time as an indicator for phase transitions of space quanta.

Experimental study in heat accumulators with a phase transition of matter

The proposed article is devoted to the study of a heat accumulator with a phase transition of a substance, which is a model of an accumulator with a semi-co- occupational heat pipe through which a coolant (water) passes at different temperatures. To intensify the heat exchange process between the coolant and the heat-storing material, the tube is fitted with longitudinal and transverse ribs, and aluminum shavings are added to the HSM composition. The experimental results make it possible to suggest that there are such values of the studied parameters (flow rate, coolant temperature) at which a further increase in the latter does not have a significant effect on the rate of processes in heat accumulators based on a phase transition.

Delay-induced phase transitions in active matter

We consider the patterns of collective motion emerging when many aligning, self-propelling units move in two dimensions while interacting through a repulsive potential and are also subject to delays and random perturbations. In this approach, delay plays the role analogous to reaction time so that a given particle is influenced by the information about the velocity and the position of the other particles in its vicinity with some time delay. To get insight into the involved complex flows and the transitions between them we use a simple model allowing – by fine-tuning of its few parameters – the observation and analysis of behaviours that are less accessible by experiments or analytic calculations and at the same time make the reproduction of experimental results possible. We report for the first time about a transition from fully ordered, polarized collective motion to disorder as a function of the increasing time delay. For a fixed intermediate value of the delay, a similar transition (from order to disorder) is obtained as the repulsion radius is increased. Our simulations show a transition from total polarization to two kinds of states: fully disordered and a kind of state which is a mixture of patches of fully disordered motion in the background of orderly moving other particles. The transition occurs as the delay time is increased and is sharp, indicating that the nature of this order–disorder transition is either of first-order or is described by a sharply decreasing linear function. Our model is a simplified version of a practical situation of quickly growing interest because time delays are expected to play an increasingly important role when the traffic of many, densely distributed autonomous drones will move around in a quasi-two-dimensional air space.

Evolution of midrapidity average transverse momentum of pions, kaons, protons and antiprotons in Au+Au collisions in (snn)1∕2= 7–39-GeV energy range from the beam energy scan program

The [Formula: see text] dependencies of the experimental average transverse momentum, [Formula: see text], of the charged pions, charged kaons, protons and antiprotons produced at midrapidity ([Formula: see text]) in [Formula: see text] collisions from the Beam Energy Scan (BES) program at the RHIC (Relativistic Heavy Ion Collider), measured by STAR Collaboration in the [Formula: see text]–39-GeV energy range, have been described quite well with the power-law model function. We have obtained [Formula: see text] inequality at all BES energies, indicating the clear mass ordering (dependence) of the power parameter [Formula: see text]. On the whole, the exponent parameter [Formula: see text] for the charged kaons as well as (anti)protons decreases noticeably with increasing [Formula: see text] collision energy from [Formula: see text][Formula: see text]GeV to [Formula: see text][Formula: see text]GeV. Drastic change observed in the energy ([Formula: see text]) dependence of the parameter [Formula: see text] for the charged kaons at [Formula: see text][Formula: see text]GeV could possibly indicate a significant change in the mechanism(s) of the charged kaon production in [Formula: see text] collisions at around [Formula: see text][Formula: see text]GeV. Significant change in the [Formula: see text] dependence of the parameter [Formula: see text] for the charged pions observed at around [Formula: see text][Formula: see text]GeV is consistent with a possible change in the mechanism(s) of the particle production in [Formula: see text] collisions at around [Formula: see text][Formula: see text]GeV, reported earlier by STAR Collaboration. Significant gaps between [Formula: see text] (protons) and [Formula: see text] (antiprotons) as well as between ([Formula: see text]) and [Formula: see text] have been seen in the region [Formula: see text]–20[Formula: see text]GeV. These gaps diminish and practically disappear with [Formula: see text] and [Formula: see text] (protons) [Formula: see text] (antiprotons) in the region [Formula: see text][Formula: see text]GeV. Altogether, the findings, regarding collision energy dependencies of the parameter [Formula: see text] for the studied particle species, could indicate the probable phase transition of a nuclear matter to the mixed phase of QGP and hadrons taking place in [Formula: see text] collisions at around [Formula: see text][Formula: see text]GeV. The differences found between parameter [Formula: see text] versus [Formula: see text] dependencies of the particles and antiparticles have been connected with the ratios of antiparticle and particle yields and differences in the mechanisms of production of particles and antiparticles. It is deduced that the exponent parameter [Formula: see text] should be sensitive to the degree of particle (system) thermalization and particle production mechanisms, and its drastic change could be related to the change in the mechanisms of particle production or/and phase transitions in the nuclear/hadronic matter.

Ridges in rotating neutron-star properties due to first order phase transitions

We identify combinations of observables for rotating neutron stars that can one day bear on the question of whether there can be first order phase transitions in the neutron matter therein. We employ the Hartle–Thorne theory for stationary, rotating neutron stars at conventional angular velocities (in the conventional pulsar and millisecond pulsar ranges) and extract three-dimensional sections of the ellipticity or the dynamical angular momentum as function of the star’s mass and angular velocity. An eventual first order phase transition in the equation of state (EoS) leaves a clear ridge (nonanalyticity) in these observables, akin to the sudden kink in popular mass–radius diagrams for static stars. Finally, we observe that static neutron stars in General Relativity (GR) will fail to be compact enough for the light ring’s position at r=3M to be outside the star, except for the most extreme equations of state. The outer light ring of a rotating star might however be formed unless the EoS softens too much, and its eventual detection can then be used to constrain the EoS (or the gravity theory).

Pre/Post-Merger Consistency Test for Gravitational Signals from Binary Neutron Star Mergers

Gravitational waves from binary neutron star (BNS) mergers can constrain nuclear models, predicting their equation of state (EOS). Matter effects on the inspiral-merger signal are encoded in the multipolar tidal polarizability parameters, whose leading order combination is sufficient to capture, with high accuracy, the key features of the merger waveform. Similar EOS-insensitive relations exist for the post-merger signal and can be used to model the emissions from the remnant. Several works suggested that the appearance of new degrees of freedom in high-density post-merger matter can be inferred by observing a violation of these EOS-insensitive relations. Here, we demonstrate a Bayesian method to test such an EOS-insensitive relation between the tidal polarizability parameters (or any other equivalent parameter) and the dominant post-merger frequency using information from the pre-and-post-merger signal. Technically, the method is similar to the inspiral-merger-ringdown consistency tests of General Relativity with binary black holes. However, differently from the latter, BNS pre/post-merger consistency tests are conceptually less informative and they only address the consistency of the assumed EOS-insensitive relation. Specifically, we discuss how such tests cannot conclusively discriminate between an EOS without respecting such a relation and the appearance of new degrees of freedom (or phase transitions) in high-density matter.

Searching for QCD critical point with light nuclei

Density fluctuations and correlations due to a first-order quark-gluon plasma to hadronic matter phase transition and its critical end point, if they remain present after the hadronic evolution in a heavy ion collisions, can lead to an enhanced production of light nuclei in these collisions. This would then result in a non-monotonic collision energy dependence of the yield ratio $$N_\text {t} N_\text {p} / N_\text {d}^2$$ of proton number $$N_\text {p}$$ , deuteron number $$N_\text {d}$$ , and triton number $$N_\text {t}$$ . Measurements of this yield ratio as a function of collision energy thus provides the possibility to probe the equation of state of strong-interaction matter and its phase diagram.

Spin polarization and anomalous magnetic moment in a ( 2+1 )-flavor Nambu–Jona-Lasinio model in a thermomagnetic background

We investigate the magnetized QCD matter and chiral phase transition in a ($2+1$)-flavor Nambu--Jona-Lasinio (NJL) model at finite temperature and chemical potential by comparing the contributions from the tensor spin polarization (TSP) and anomalous magnetic moment (AMM) of quarks. For light $u$ and $d$ quarks, when TSP and AMM are not considered, the magnetized system is characterized by magnetic catalysis. The introduction of TSP will further enhance the magnetic catalytic characteristics. On the other hand, when AMM is introduced, the phase-transition temperature decreases with the magnetic field, which is the feature of inverse magnetic catalysis. The phase diagram of $u$ and $d$ quarks will change from the crossover phase transition to the first order phase transition with the increase of magnetic field and chemical potential when AMM is induced. The phase diagram will not change from the crossover phase transition to the first-order phase transition when TSP is induced. For the phase diagram of strange $s$ quark, whether TSP or AMM is induced, the phase diagram will keep a crossover phase transition with the increase of magnetic field and chemical potential.

Fluctuations near the liquid-gas and chiral phase transitions in hadronic matter

We investigate the fluctuations of the net-baryon number density in dense hadronic matter. Chiral dynamics is modeled via the parity doublet Lagrangian, and the mean-field approximation is employed to account for chiral criticality. We focus on the qualitative properties and systematics of the second-order susceptibility of the net-baryon number density for individual positive- and negative-parity nucleons whose masses become degenerate at the chiral restoration. It is shown that the second-order susceptibility of the positive-parity state can become negative when the chiral symmetry is restored, as a natural consequence of the unique relationship of the mass to the order parameter. Moreover, we find that such negative fluctuations are indicative of approaching the critical point on the chiral phase boundary. Our results may have consequences for the interpretation of the experimental data on net-proton fluctuations in heavy-ion collisions.

Inference of the sound speed and related properties of neutron stars

Information on the phase structure of strongly interacting matter at high baryon densities can be gained from observations of neutron stars and their detailed analysis. In the present work Bayesian inference methods are used to set constraints on the speed of sound in the interior of neutron stars, based on recent multimessenger data in combination with limiting conditions from nuclear physics at low densities. Two general parametric representations are introduced for the sound speed ${c}_{s}$ in order to examine the independence with respect to choices for the parametrization of priors. Credible regions for neutron star properties are analyzed, in particular with reference to the quest for possible phase transitions in cold dense matter. The evaluation of Bayes factors implies extreme evidence for a violation of the conformal bound, ${c}_{s}^{2}\ensuremath{\le}1/3$, inside neutron stars. Given the presently existing data base, it can be concluded that the occurrence of a first-order phase transition in the core of even a two-solar-mass neutron star is unlikely, while a continuous crossover cannot be ruled out. At the same time it is pointed out that the discovery of a superheavy neutron star with a mass $M\ensuremath{\sim}2.3--2.4\text{ }\text{ }{M}_{\ensuremath{\bigodot}}$ would strengthen evidence for a phase change in the deep interior of the star.

Detecting and characterizing phase transitions in active matter using entropy.

A major challenge in the study of active matter lies in quantitative characterization of phases and transitions between them. We show how the entropy of a collection of active objects can be used to classify regimes and spatial patterns in their collective behavior. Specifically, we estimate the contributions to the total entropy from correlations between the degrees of freedom of position and orientation. This analysis pin-points the flocking transition in the Vicsek model while clarifying the physical mechanism behind the transition. When applied to experiments on swarming Bacillus subtilis with different cell aspect ratios and overall bacterial area fractions, the entropy analysis reveals a rich phase diagram with transitions between qualitatively different swarm statistics. We discuss physical and biological implications of these findings.

Phase transitions driven by topological excitations and their tensor network approach

The fundamental concepts of phases of matter and thermal phase transitions constitute the cornerstone of our understanding of the physical universe. The historical development of the phase transition theory from Landau's spontaneous symmetry breaking paradigm to modern topological phase transition theories represents a major milestone in the evolution of numerous scientific disciplines. From the perspective of emergent philosophy, the interplay of topological excitations leads to enriched physical phenomena. One prominent prototype is the Berezinskii-Kosterlitz-Thouless (BKT) phase transition, where unbinding of integer vortices occurs in the absence of spontaneous breaking of continuous <i>U</i>(1) symmetry. Using the state-of-the-art tensor network methods, we express the partition function of the two-dimensional <i>XY</i>-related system in terms of a product of one-dimensional transfer operators. From the singularities of the entanglement entropy of the one-dimensional transfer operator, we accurately determine the complete phase diagram of the partition function. This method provides new insights into the emergent phenomenon driven by topological excitations, and sheds new light on future studies of 2D systems with continuous symmetries.

How to Select Phase Change Materials for Tuning Condensation and Frosting?

AbstractSynthetic surfaces engineered to regulate phase transitions of matter and exercise control over its undesired accrual (liquid or solid) play a pivotal role in diverse industrial applications. Over the years, the design of repellant surfaces has transitioned from solely modifying the surface texture and chemistry to identifying novel material systems. In this study, selection criteria are established to identify bio‐friendly phase change materials (PCMs) from an extensive library of vegetable‐based/organic/essential oils that can thermally respond by harnessing the latent heat released during condensation and thereby delaying ice/frost formation in the very frigid ambient that is detrimental to its functionality. Concurrently, a comprehensive investigation is conducted to elucidate the relation between microscale heat transport phenomena during condensation and the resulting macroscopic effects (e.g., delayed droplet freezing) on various solidified PCMs as a function of their inherent thermo‐mechanical properties. In addition, to freeze protection, many properties that are responsive to the thermal reflex of the surface, such as the ability to dynamically tune optical transparency, moisture harvesting, ice shedding, and quick in‐field repairability, are achievable, resulting in the development of protective coatings capable of spanning a wide range of functionalities and thereby having a distinctive edge over conventional solutions.