Quark Matter Research Papers - Academia.edu (original) (raw)

2025

We present an inverted analytic relation between neutron-star mass and radius, derived from the same compactness law that reproduces observed radii from known masses with meter-scale precision. Instead of M → R, we now solve the relation in reverse to obtain R → M , yielding a closed-form expression for mass using only the measured stellar radius. The inverted law is validated on a 58-object calibration set with reliable dynamical masses, reproducing them with typical deviations below 0.1%. We then apply the method to 19 neutron stars with accurately measured radii but unknown or poorly constrained masses, producing specific mass predictions with propagated uncertainties. These predictions form a falsifiable set for future observational tests.

2025, The Prion

We continue to derive the standard models particles without free parameters. Now the Prion.

2025, International Journal of Astronomy and Astrophysics

Considering Bianchi type III space-time we present the model Universe containing strange quark matter which is expanding, anisotropic, with a sign of dark energy that help in accelerated expansion of this Universe. It is also seen that the model Universe contains both particles and strings but ultimately will have fluid containing particles only. This model which we consider here is acceptable in view of the present observations of the Universe. Some physical and geometrical properties are also discussed.

2025, particle production proton proton collision

Proton-proton collision is a simple system to investigate nuclear matter and it is considered to be a guide for more sophisticated processes in the proton-nucleus and the nucleus-nucleus collisions. In this article, the authors present a phenomological study of how the mechanism of particle production in pp interaction changes over a wide range of interaction energy. This study is done on data of charged particle produced in pp experiments at different values of energy. Some of these data give the created particles classified as hadrons, baryons and mesons, which help us compare between production of different particles. This might probe some changes in the state of nuclear matter and identify the mechanism of interaction.

2025, Astrophysics and Space Science

We have discussed non-linear stability in photogravitational non-planar restricted three body problem with oblate smaller primary. By photogravitational we mean that both primaries are radiating. We normalised the Hamiltonian using Lie transform as in . We transformed the system into Birkhoff's normal form. Lie transforms reduce the system to an equivalent simpler system which is immediately solvable. Applying Arnolds theorem, we have found non-linear stability criteria. We conclude that L 6 is stable. We plotted graphs for (ω 1 , D 2 ). They are rectangular hyperbola.

2025, arXiv (Cornell University)

We investigate baryon transport in relativistic heavy-ion collisions at energies reached at the CERN Super Proton Synchrotron (SPS), BNL Relativistic Heavy-Ion Collider (RHIC), and CERN's Large Hadron Collider (LHC) in the model of saturation. An analytical scaling law is derived within the color glass condensate framework based on small-coupling QCD. Transverse momentum spectra, net-baryon rapidity distributions, and their energy, mass, and centrality dependencies are well described. In comparison with RHIC data in Au + Au collisions at √ s N N = 62.4 and 200 GeV, the gradual approach to the gluon saturation regime is investigated and limits for the saturation-scale exponent are determined. Predictions for net-baryon rapidity spectra and the mean rapidity loss in central Pb + Pb collisions at LHC energies of √ s N N = 5.52 TeV are made.

2025, Physics Letters B

We investigate the process of Abelian pair production in the presence of strong inhomogeneous and time-dependent external electric fields. The spatial dependence of the external field is motivated by a non-Abelian color flux tube in heavy-ion collisions. We show that the inhomogeneity significantly increase the particle yield compared to that in the commonly used models with a constant and homogeneous field. Moreover our results indicate that in contrast to the latter, most of the particles are produced at the interface of the field profile in accordance with Heisenberg's prediction.

2025, EPJ Web of Conferences

2025, Journal of Physics G

We discuss shear viscosity of the quark matter by using Kubo formula. The shear viscosity is calculated in the framework of the quasi-particle RPA for the Nambu-Jona-Lasinio model. We obtain a formula that the shear viscosity is expressed by the quadratic form of the quark spectral function in the chiral symmetric phase. The magnitude of the shear viscosity is discussed assuming the Breit-Wigner type for the spectral function.

2025, Progress of Theoretical and Experimental Physics

Superconductivity of quark matter is investigated at high density. It is found that the superconducting (BCS) state is stable over a wide range of the quark density and becomes unstable at the critical density 10 < pc < 100 (fm-3 ) due to the asymptotic freedom of QCD. It is suggested that the compressibility is discontinuous across the critical density.

2025, Progress of Theoretical Physics

We discuss the color-superconductivity and its effect on the cooling behavior of strange quark stars. The neutrino emissivity and specific heat of quark matter are calculated within the BCS theory. In the superconducting phase, the emissivity decreases and causes suppression of the cooling rate. It is shown that the phase transition leads to a sudden discontinuous suppression of the cooling rate in cooperation with the specific heat.

2025, Progress of Theoretical Physics

2025, Journal of Physics G: Nuclear and Particle Physics

2025, Advances in Space Research

Richardson potential is an phenomenological interquark interaction taking care of two aspects of QCD, namely the asymptotic freedom and the confinement. The original potential has a scale parameter having value ∼ 400 M eV and is well tested in hadronic property calculations. This potential was then used in strange star calculation. Strange stars are very compact stars composed of strange quark matter i.e. a very high density strange quark phase consisting of deconfined u, d and s quarks. Here the value of the scale parameter was taken as 100 M eV . The argument was that for a deconfined quark system like a strange star, the scale parameter may have a value quite different from that used in hadronic sector. To remove this discrepancy we introduced two scale parameters in the potential, one for the asymptotic freedom part and the other for the confining part. With suitable values of the parameters, this modified potential has been successfully used in both baryonic property and strange star calculations. The Equation of States obtained with the modified potential are also used to obtain mass-radius relations for the strange stars.

2025

This speculative work attempts to organize and rationalize anecdotal and fringe reports on levitation, anti-gravity, and field-based phenomena. While most accounts remain unverified, we propose a coherent framework that links these ideas through tensorial structures, weighted symmetries, and toroidal field architectures. The goal is not to provide actionable instructions, but to offer a system of reason that allows practitioners or theorists to understand their own apparatus beyond intuitive knob-turning. Though approached philosophically, the discussion necessarily engages formal equations to articulate the underlying patterns, revealing a conceptual bridge between physical theory, consciousness, and engineered systems.

2025, From Quantum Strings to Cosmic Acceleration A Rigorous 11-Dimensional Unification Framework via the EQST-GP Model

This paper presents the Expanded Quantum String Theory with Gluonic Plasma (EQST-GP), a comprehensive framework for a Theory of Everything (TOE) that unifies quantum string theory with gluonic plasma dynamics while incorporating elements from loop quantum gravity and the Standard Model. The model successfully derives all fundamental constants from first principles, identifies dark matter as a gluonic quark foam plasma with negative Casimir-like energy, and provides a novel resolution to the Hubble tension through dynamic cosmological evolution. Key innovations include: (1) rigorous derivation of the proton mass (m p = 938.272 081 3 MeV) with 1.6 ppm accuracy; (2) prediction of the fine-structure constant (α-1 = 137.035999084(51)) matching experimental precision; (3) resolution of cosmological parameters (H 0 = 67.36kms-1 , Ω m = 0.3111) consistent with DESI 2025 and JWST observations; (4) complete derivation of CKM and PMNS matrices from string compactification; and (5) extension to quantum-inspired artificial intelligence optimization. The model demonstrates exceptional agreement with experimental data across 25 independent precision tests while maintaining mathematical rigor and predictive power.

2025

We investigate the impact of non-Hermiticity on the thermodynamic properties of interacting fermions by examining bilinear extensions to the 3 + 1 dimensional SU (2)-symmetric Nambu-Jona-Lasinio (NJL) model of quantum chromodynamics at finite temperature and chemical potential. The system is modified through the anti-PT-symmetric pseudoscalar bilinear ψγ5ψ and the PTsymmetric pseudovector bilinear iBν ψγ5γ ν ψ, introduced with a coupling g. Beyond the possibility of dynamical fermion mass generation at finite temperature and chemical potential, our findings establish model-dependent changes in the position of the chiral phase transition and the critical end-point. These are tunable with respect to g in the former case, and both g and |B|/B0 in the latter case, for both lightlike and spacelike fields. Moreover, the behavior of the quark number, entropy, pressure, and energy densities signal a potential fermion or antifermion excess compared to the standard NJL model, due to the pseudoscalar and pseudovector extension respectively. In both cases regions with negative interaction measure I = -3p are found. Future indications of such behaviors in strongly interacting fermion systems, for example in the context of neutron star physics, may point toward the presence of non-Hermitian contributions. These trends provide a first indication of curious potential mechanisms for producing non-Hermitian baryon asymmetry. In addition, the formalism described in this study is expected to apply more generally to other Hamiltonians with four-fermion interactions and thus the effects of the non-Hermitian bilinears are likely to be generic.

2025, arXiv (Cornell University)

We solve the Combustion adiabat (CA) or the Chapman-Jouget adiabat equation to study the phase transition (PT) of a neutron star (NS) to a quark star (QS). The hadronic matter and quark matter equation of states are used to calculate the matter velocities on either side of the shock front. The CA with the hadronic matter as an input is solved to obtain the corresponding quark matter values. The maximum of the quark pressure is reflected in the retracing of the path in the CA curve. The downstream quark pressure maximum implies towards a maximum mass limit of a phase transformed QS which is different from the regular mass limit of an ordinary QS. Further, the characterization of velocities suggest that the PT from NS to QS is not always feasible from the center of the star. The possible mode of combustion in NSs is likely to be a slow deflagration in most of the low and intermediate density range. The result is crucial and emphasizes on the fact that PT in NSs does not always starts from the center and sometimes a NS does not suffers a PT at all.

2025, arXiv (Cornell University)

Compact astrophysical objects are a window for the study of strongly interacting nuclear matter given the conditions in their interiors, which are not reproduced in a laboratory environment. Much has been debated about their composition with possibilities ranging from a simple mixture of mostly protons and neutrons to deconfined quark matter. Recent observations on the mass of two pulsars, PSR J1614-2230 and PSR J0348+0432, have posed a great restriction on their composition, since the equation of state must be hard enough to support masses of about at least two solar masses. The onset of quarks tends to soften the equation of state, but it can get substantially stiffer since in the high-dense medium a repulsive vector interaction channel is opened. Nevertheless, we show that once gluon effects are considered, the equation of state of quark matter in the color-flavorlocked phase of color superconductivity becomes softer decreasing the maximum stellar mass that can be reached when not considering their influence. This may indicate that stars made entirely of color superconducting matter can only be favored to describe compact stars if the repulsive vector constant is high enough.

2025, arXiv (Cornell University)

In this talk I review some of the main findings on magnetism in color superconductivity. The physical characteristic of the different phases that are reached by increasing the applied magnetic field in a three-flavor color superconductor at asymptotically high densities are discussed. A mechanism to boost a seed magnetic field in high-dense quark matter is presented. Also, it is shown how a magnetic field can be generated in a color superconductor at moderate densities. Possible implications of these results for the astrophysics of magnetized compact objects are indicated.

2025, Physical Review C

We present results on strange and multi-strange particle production in Au+Au collisions at √ sNN = 62.4 GeV as measured with the STAR detector at RHIC. Mid-rapidity transverse momentum spectra and integrated yields of K 0 S , Λ, Ξ, Ω and their anti-particles are presented for different centrality classes. The particle yields and ratios follow a smooth energy dependence. Chemical freeze-out parameters, temperature, baryon chemical potential and strangeness saturation factor obtained from the particle yields are presented. Intermediate transverse momentum (pT ) phenomena are discussed based on the ratio of the measured baryon-to-meson spectra and nuclear modification factor. The centrality dependence of various measurements presented show a similar behavior as seen in Au+Au collisions at √ sNN = 200 GeV.

2025, Extension Modal of String and (M) Theory Expanded Quantum String Theory with Gluonic Plasma (EQST-GP

This paper presents a comprehensive framework for a Theory of Everything (TOE) by integrating quantum string theory with gluonic plasma dynamics, incorporating elements from loop quantum gravity and the Standard Model. The Expanded Quantum String Theory with Gluonic Plasma (EQST-GP) model unifies gravitational, electromagnetic, strong, and weak interactions while addressing dark matter as a gluonic quark foam plasma with negative Casimir-like energy. Key innovations include derivations of fundamental constants from first principles, predictions for testable experiments, and extensions to artificial intelligence loss functions for quantum-inspired optimization. The model adheres to Occam's razor, providing a minimal yet complete description of the universe.

2025, Expanded Quantum String Theory with Gluonic Plasma (EQST-GP)

The pursuit of a unified framework connecting quantum theory, gravitation, and cosmology has historically been constrained within academic walls. Yet, history shows that breakthroughs— from Einstein’s relativity to the Higgs... more

2025

Thermal models have been used to successfully describe the hadron yields from heavy ion collisions at a variety of energies. For root(S)<17 GeV this has usually been done using yields integrated over 4pi but at the higher energies available at RHIC, yields measured at central rapidity have been used. Recent BRAHMS data allows us to test whether thermal models can be generalized to describe the rapidity dependence of particle ratios. We have used the THERMUS package to fit BRAHMS data for the 5% most central Au+Au collisions for several rapidities at root(S) = 62 and 200 GeV. We have found a relationship between the strange and light quark chemical potentials, muS = 0.21 +-0.01muB. Using this relation we are able to describe the energy dependence of Lambda, Xsi and Omega ratios from other experiments. We also find that the chemical potentials are consistent with limiting fragmentation.

2025, Monthly Notices of the Royal Astronomical Society

We investigate the deposition of energy due to the annihilations of neutrinos and antineutrinos on the rotation axis of rotating neutron and quark stars, respectively. The source of the neutrinos is assumed to be a neutrino-cooled accretion disc around the compact object. Under the assumption of the separability of the neutrino null geodesic equation of motion, we obtain the general relativistic expression of the energy deposition rate for arbitrary stationary and axisymmetric space-times. The neutrino trajectories are obtained by using a ray tracing algorithm, based on numerically solving the Hamilton-Jacobi equation for neutrinos by reversing the proper time evolution. We obtain the energy deposition rates for several classes of rotating neutron stars, described by different equations of state of the neutron matter, and for quark stars, described by the MIT bag model equation of state and in the colour-flavourlocked phase, respectively. The electron-positron energy deposition rate on the rotation axis of rotating neutron and quark stars is studied for two accretion disc models (isothermal disc and accretion disc in thermodynamical equilibrium). Rotation and general relativistic effects modify the total annihilation rate of the neutrino-antineutrino pairs on the rotation axis of compact stellar general relativistic objects, as measured by an observer at infinity. The differences in the equations of state for neutron and quark matter also have important effects on the spatial distribution of the energy deposition rate by neutrino-antineutrino annihilation.

2025

Neutron stars provide unique laboratories for studying matter under extreme conditions, from the outer atmosphere to the ultra-dense core. This review covers the formation of neutron stars in core-collapse supernovae and details their layered internal structure, including the atmosphere, envelope, crust, and dense nuclear core. We discuss key physical processes such as neutrino cooling, superfluidity, superconductivity, and the role of quantum condensates in shaping neutron star behavior. The interplay of superfluid vortices and magnetic flux tubes explains observed phenomena like pulsar glitches, while strong magnetic fields govern spin evolution and high-energy emission. Advances in mass and radius measurements from X-ray and gravitational-wave observations are constraining the equation of state of dense nuclear matter. By combining theoretical insights and observations, this work summarizes current knowledge of neutron star interiors and outlines future pathways for understanding matter at supranuclear densities.

2025, arXiv (Cornell University)

It is shown that planar topological effective gauge theory with dynamics, acquires corrections to angular momentum beyond the well-known topological photon spin, the latter arising from interactions with parity-breaking massive fermions. In the nonrelativistic limit, a first quantized Schrödinger representation is possible where the topological and kinetic terms decouple, the latter contributing to angular momentum and compete with the centrifugal barrier. This results in shallow resonances of Efimov kind, which may be verified in planar physical systems.

2025, Proceedings of the scientific conference «Crown of Knowledge»

Natural science is experiencing a deep conceptual crisis, the roots of which go back in the fundamental contradictions between: general relativity and quantum mechanics, determinism and free will, materialism and idealism. The ontology of the Infinite Field of potencies offers a radically new approach that overcomes these contradictions by rethinking the very nature of reality.

2025

We present a model of fast hadronization of constituent quark matter in relativistic heavy ion collisions based on rate equations and capture cross sections in non-relativistic potential. We utilize a thermodynamically consistent approach with a non-ideal equation of state including correlation terms based on string phenomenology. We investigate strange and non-strange particle ratios observed in CERN SPS experiments.

2025, Journal of Physics G: Nuclear and Particle Physics

We study the production of charm mesons and other charm baryons from quark matter at CERN SPS and RHIC energies. Using quark coalescence models as hadronization mechanism, we predict particle ratios, absolute yields and transverse... more

2025, Journal of Physics G: Nuclear and Particle Physics

Photon-tagged correlations may be useful to determine how the dense partonic medium produced in heavy-ion collisions affects the fragmentation of highenergy quarks and gluons into a leading hadron. In these proceedings, I discuss the kinematic requirements for the hadron and the prompt photon transverse momentum cuts. A case study at LHC energy, tagging on p ⊥γ ≥ 20 GeV and p ⊥γ ≥ 50 GeV photons, is then briefly examined.

2025, Journal of Physics G: Nuclear and Particle Physics

We use holographic techniques to study meson quasiparticles moving through a thermal plasma in N = 2 super-Yang-Mills theory, with gauge group SU (N c ) and coupled to N f flavours of fundamental matter. This holographic approach reliably describes the system at large N c , large 't Hooft coupling and N f /N c ≪ 1. The meson states are destabilized by introducing a small quark density n q . Spectral functions are used to examine the dispersion relations of these quasiparticles. In a low-momentum regime, the quasiparticles approach a limiting velocity which can be significantly less than the speed of light. In this regime, the widths of the quasiparticles also rise dramatically as their momentum approaches a critical value Õ crit . While the spectral functions do not display isolated resonances for Õ > Õ crit , the dispersion relations can be extended into this high-momentum regime by studying the dual quasinormal modes. A preliminary qualitative analysis of these modes suggests that the group velocity rises to the speed of light for Õ ≫ Õ crit .

2025, Physical Review D

We explore the relevance of confinement in quark matter models for the possible quark core of neutron stars. For the quark phase, we adopt the equation of state (EoS) derived with the Field Correlator Method, extended to the zero temperature limit. For the hadronic phase, we use the microscopic Brueckner-Hartree-Fock many-body theory. We find that the currently adopted value of the gluon condensate G2 ≃ 0.006-0.007 GeV 4 , which gives a critical temperature Tc ≃ 170 MeV, produces maximum masses which are only marginally consistent with the observational limit, while larger masses are possible if the gluon condensate is increased.

2025

This report examines the relationship between the hadron creation energy predicted by Mo-theory, denoted E M o , and the Hagedorn temperature T H obtained from hadronic resonance data. Using the published value of T H ≈ 174 MeV derived from hadronic resonance analysis, we compare it to the Mo-theory prediction of hadron energy. The comparison provides insight into how Mo-theory aligns with conventional quantum chromodynamics (QCD) estimates of hadronic matter formation.

2025

This paper presents a novel framework for calculating hadron masses within the Information-Cognitive Compression Field (ICCF) model. The ICCF approach unifies quantum field theory, thermodynamics, and information geometry to explain particle mass generation, particularly focusing on hadrons such as protons, neutrons, and mesons. The model introduces the concept of Integrated Information Entities (IIEs) and causal interactions that determine the stability and mass of particles. We derive the ICCF hadron mass formula, which incorporates three major contributions: the bare compression energy of quarks, the energy stored in causal strings connecting quarks, and the saturation energy released when the system reaches causal stability. Through a series of approximations, we demonstrate the calculation of the proton mass, with predictions that align with experimental values. Additionally, the model allows for predictions of the mass spectrum of other hadrons, including strange hadrons, and provides insights into their decay modes, branching ratios, and resonance states, using thermodynamic principles such as entropy release and topological structure overlap. This framework offers a comprehensive, calculable model for particle mass, expanding the potential for new experimental predictions and verification.

2025, SSRN Electronic Journal

The XMM-Newton observatory shows evidence, with a 11 σ confidence level, for seasonal variation of the X-ray background in the near-Earth environment in the 2-6 keV energy range . The authors argue that the observed seasonal variation suggests a possible link with dark matter. We propose an explanation which involves the Axion Quark Nugget (AQN) dark matter model. In our proposal, AQNs can cross the Earth and emit high energy photons at their exit. We show that the emitted spectrum is consistent with [1], and that our calculation is not sensitive to the specific details of the model. Our proposal predicts a large seasonal variation, on the level of 20-25%, much larger than conventional dark matter models (1-10%). Since the AQN emission spectrum extends up to ∼100 keV, well beyond the keV sensitivity of XMM-Newton, we predict the AQN contribution to the hard X-ray and γ-ray backgrounds in the Earth's environment. The Gamma-Ray Burst Monitor (GBM) instrument, aboard the FERMI telescope, is sensitive to the 8 keV-40 MeV energy band. The NuSTAR (Nuclear Spectroscopic Telescope Array) is a NASA space based X ray telescope which operates in the range 3 to 79 keV is also sensitive to higher energy bands. We suggest that the multi-year archival data from the GBM or NuSTAR could be used to search for a seasonal variation in the near-Earth environment up to 100 keV as a future test of the AQN framework.

2025, Physics Letters B

It has been recently argued that there is a strong component of the diffuse far-ultraviolet (FUV) background which is hard to explain by conventional physics in terms of the dust-scattered starlight. We propose that this excess in FUV radiation might be result of the dark matter annihilation events within the so-called axion quark nugget (AQN) dark matter model, which was originally invented for completely different purpose to explain the observed similarity between the dark and the visible components in the Universe, i.e. ΩDM ∼ Ω visible . We support this proposal by demonstrating that intensity and the spectral features of the AQN induced emissions are consistent with the corresponding characteristics of the observed excess of the FUV radiation.

2025, Physical Review D

We study a testable dark matter (DM) model outside of the standard WIMP paradigm in which the observed ratio Ω dark Ω visible for visible and dark matter densities finds its natural explanation as a result of their common QCD origin when both types of matter (DM and visible) are formed at the QCD phase transition and both are proportional to Λ QCD . Instead of the conventional "baryogenesis" mechanism we advocate a paradigm when the "baryogenesis" is actually a charge separation process which occur in the presence of the CP odd axion field a(x). In this scenario the global baryon number of the Universe remains zero, while the unobserved antibaryon charge is hidden in form of heavy nuggets, similar to Witten's strangelets and compromise the DM of the Universe. In the present work we study in great detail a possible formation mechanism of such macroscopically large heavy objects. We argue that the nuggets will be inevitably produced during the QCD phase transition as a result of Kibble-Zurek mechanism on formation of the topological defects during a phase transition. Relevant topological defects in our scenario are the closed bubbles made of the N DW = 1 axion domain walls. These bubbles, in general, accrete the baryon (or antibaryon) charge, which eventually result in formation of the nuggets and anti-nuggets carrying a huge baryon (antibaryon) charge. A typical size and the baryon charge of these macroscopically large objects is mainly determined by the axion mass m a . However, the main consequence of the model, Ω dark ≈ Ω visible is insensitive to the axion mass which may assume any value within the observationally allowed window 10 -6 eV m a 10 -3 eV. We also estimate the baryon to entropy ratio η ≡ n B /n γ ∼ 10 -10 within this scenario. Finally, we comment on implications of these results to the axion search experiments, including microwave cavity and the Orpheus experiments. The results of this thesis has been published on arXiv as Xunyu Liang and Ariel Zhitnitsky, arXiv:1606.00435 [hep-ph]. Section 2.4 and appendices were my work, but also being improved by Ariel Zhitnitsky, especially Appendix A, into a more logical framework. Additionally, the inclusion of the viscosity term was suggested by me. The rest of new results, chapter 2, 3, and 5, presented in this thesis was done and written by Ariel Zhitnitsky. Also, the remaining review chapters were written by Ariel Zhitnitsky.

2025, Physical Review C

We suggest a mechanism that may resolve a conflict between the precession of a neutron star and the widely accepted idea that protons in the bulk of the neutron star form a type-II superconductor. We will show that if there is a persistent, non-dissipating current running along the magnetic flux tubes the force between magnetic flux tubes may be attractive, resulting in a type-I, rather than a type-II, superconductor. If this is the case, the conflict between the observed precession and the canonical estimation of the Landau-Ginzburg parameter κ > 1/ √ 2 (which suggests type-II behaviour) will automatically be resolved. We calculate the interaction between two vortices, each carrying a current j, and demonstrate that when j > c 2qλ , where q is the charge of the Cooper pair and λ is the Meissner penetration depth, a superconductor is always type-I, even when the cannonical Landau-Ginzburg parameter κ indicates type-II behaviour. If this condition is met, the magnetic field is completely expelled from the superconducting regions of the neutron star. This leads to the formation of the intermediate state, where alternating domains of superconducting matter and normal matter coexist. We further argue that even when the induced current is small j < c 2qλ the vortex Abrikosov lattice will nevertheless be destroyed due to the helical instability studied previously in many condensed matter systems. This would also resolve the apparent contradiction with the precession of the neutron stars. We also discuss some instances where anomalous induced currents may play a crucial role, such as in neutron star kicks, pulsar glitches, the toroidal magnetic field and the magnetic helicity.

2025, Physical Review D

Dark Matter (DM) being the vital ingredient in the cosmos, still remains a mystery. Standard assumption is that the collisionless cold dark matter (CCDM) particles are represented by some weakly interacting fundamental fields which can not be associated with any standard quarks or leptons. However, recent analyses of structure on galactic and sub-galactic scales have suggested discrepancies and stimulated numerous alternative proposals including, e.g. Self-Interacting dark matter, Self-Annihilating dark matter, Decaying dark matter, to name just a few. We propose the alternative to the standard assumption about the nature of DM particles (which are typically assumed to be weakly interacting fundamental point -like particles, yet to be discovered). Our proposal is based on the idea that DM particles are strongly interacting composite macroscopically large objects which made of well known light quarks (or even antiquarks). The required weakness of the DM particle interactions is guaranteed by a small geometrical factor ǫ ∼ area volume ∼ B -1/3 ≪ 1 of the composite objects with a large baryon charge B ≫ 1, rather than by a weak coupling constant of a new field. We argue that the interaction between hadronic matter and composite dark objects does not spoil the desired properties of the latter as cold matter. We also argue that such a scenario does not contradict to the current observational data. Rather, it has natural explanations of many observed data, such as ΩDM /ΩB ∼ 1 or 511 KeV line from the bulge of our galaxy. We also suggest that composite dark matter may modify the dynamics of structure formation in the central overdense regions of galaxies. We also present a number of other cosmological/astrophysical observations which indirectly support the novel concept of DM nature.

2025, Journal of Cosmology and Astroparticle Physics

The effects of anomalies in high density QCD are striking. We consider a direct application of one of these effects, namely topological currents, on the physics of neutron stars. All the elements required for topological currents are present in neutron stars: degenerate matter, large magnetic fields, and parity violating processes. These conditions lead to the creation of vector currents capable of carrying momentum and inducing magnetic fields. We estimate the size of these currents for many representative states of dense matter in the neutron star and argue that they could be responsible for the large proper motion of neutron stars (kicks), the toroidal magnetic field and finite magnetic helicity needed for stability of the poloidal field, and the resolution of the conflict between type-II superconductivity and precession. Though these observational effects appear unrelated, they likely originate from the same physics-they are all P-odd phenomena that stem from a topological current generated by parity violation.

2025, Journal of Cosmology and Astroparticle Physics

We discuss a novel cold dark matter candidate which is formed from the ordinary quarks during the QCD phase transition when the axion domain wall undergoes an unchecked collapse due to the tension in the wall. If a large number of quarks is trapped inside the bulk of a closed axion domain wall, the collapse stops due to the internal Fermi pressure. In this case the system in the bulk, may reach the critical density when it undergoes a phase transition to a color superconducting phase with the ground state being the quark condensate, similar to the Cooper pairs in BCS theory. If this happens, the new state of matter representing the diquark condensate with a large baryon number B ∼ 10 32 becomes a stable soliton-like configuration. Consequently, it may serve as a novel cold dark matter candidate.

2025, Physical Review Letters

The NA52 experiment searches for long-lived massive strange quark matter particles, so-called strangelets, produced in Pb-Pb collisions at a beam momentum of p lab 158 A GeV͞c. Upper limits for the production of strangelets at zero degree production angle covering a mass to charge ratio up to 120 GeV͞c 2 and lifetimes t lab * 1.2 ms are given. The data presented here were taken during the 1994 lead beam running period at

2025, Astronomy and Astrophysics

The potential role of a diocotron instability in causing drifting sub-pulses in radio pulsar emission is investigated for aligned magnetic rotators. It is assumed that the out-flowing plasma above a pulsar polar cap consists of an initially axially symmetric, hollow beam of relativistic electron positron pair plasma which carries an electric charge as well as a current. The occurrence of instability depends on shear in the angular velocity distribution of the beam as a function of axial distance. Instability occurs under typical pulsar conditions at mode numbers ≤40. It destroys the symmetry of the equilibrium configuration and leads to a carousel of density columns which rotates at fixed angular pattern speed. The process is applied to two pulsars with observed carousels of drifting sub-pulses, and the diocotron instability at corresponding mode number and axial distance is used as a diagnostic for the charge and current density of the polar flow.

2025, Astronomy & Astrophysics

2025

GO*™-* undir °""2i.^L AC0M4OMMOO. tool**. r paMWad form o* **• <JU ^!L ectures presented at the 10th INS-Kikuchi Spring School on Quarks and Nuclei, Shimoda, Japan, April 1987 DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States flfl f"\ ^3 I ^_ |^L Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Referent* herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views DISTRIBUTION' OF 11WS U5u : J~{\z}il lh UNLIMITED and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

2025

We give a pedagogical review of Higgs boson low-energy theorems and their applications in the study of light Higgs boson interactions with mesons and baryons. In particular, it is shown how to combine the chiral Lagrangian method with the Higgs low-energy theorems to obtain predictions for the interaction of Higgs bosons and pseudoscalar mesons. Finally, we discuss the relation between the low-energy theorems and a technique which makes use of the trace of the QCD energy-momentum tensor.

2025, The European Physical Journal C

Ratios of the ψ ′ over the J/ψ production cross sections in the dilepton channel for C, Ti and W targets have been measured in 920 GeV proton-nucleus interactions with the HERA-B detector at the HERA storage ring. The ψ ′ and J/ψ states were reconstructed in both the µ + µ -and the e + e -decay modes. The measurements covered the kinematic range -0.35 ≤ xF ≤ 0.1 with transverse momentum pT ≤ 4.5 GeV/c. The ψ ′ to J/ψ production ratio is almost constant in the covered xF range and shows a slow increase with pT . The angular dependence of the ratio has been used to measure the difference of the ψ ′ and J/ψ polarization. All results for the muon and electron decay channels are in good agreement: their ratio, averaged over all events, is R ψ ′ (µ)/R ψ ′ (e) = 1.00 ± 0.08 ± 0.04. This result constitutes a new, direct experimental constraint on the double ratio of branching fractions, (B ′ (µ) • B(e)) / (B(µ) • B ′ (e)), of ψ ′ and J/ψ in the two channels.

2025, The European Physical Journal C

Measurements of the kinematic distributions of J /ψ mesons produced in p-C, p-Ti and p-W collisions at √ s = 41.6 GeV in the Feynman-x region -0.34 < x F < 0.14 and for transverse momentum up to p T = 5.4 GeV/c are presented. The x F and p T dependencies of the nuclear suppression parameter, α, are also given. The results are based on 2.4 × 10 5 J /ψ mesons reconstructed in both the e + e -and μ + μ -decay channels. The data have been collected by the HERA-B experiment at the HERA proton ring of the DESY laboratory. The measurement explores the negative region of x F for the first time. The average value of α in the measured x F region is 0.981 ± 0.015. The data suggest that the strong nuclear suppression of J /ψ production previously observed at high x F turns into an enhancement at negative x F .