Journal Description
Particles
Particles
is an international, open access, peer-reviewed journal covering all aspects of nuclear physics, particle physics and astrophysics science, and is published quarterly online by MDPI.
- Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
- High Visibility: indexed within Scopus, ESCI (Web of Science), Inspec, CAPlus / SciFinder, and other databases.
- Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 22.5 days after submission; acceptance to publication is undertaken in 4.6 days (median values for papers published in this journal in the first half of 2023).
- Recognition of Reviewers: reviewers who provide timely, thorough peer-review reports receive vouchers entitling them to a discount on the APC of their next publication in any MDPI journal, in appreciation of the work done.
Impact Factor:
1.4 (2022);
5-Year Impact Factor:
1.3 (2022)
Latest Articles
R-Symmetries and Curvature Constraints in A-Twisted Heterotic Landau–Ginzburg Models
Particles 2023, 6(3), 746-761; https://doi.org/10.3390/particles6030047 - 07 Aug 2023
Abstract
In this paper, we discuss various aspects of a class of A-twisted heterotic Landau–Ginzburg models on a Kähler variety X. We provide a classification of the R-symmetries in these models which allow the A-twist to be implemented, focusing on the case in
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In this paper, we discuss various aspects of a class of A-twisted heterotic Landau–Ginzburg models on a Kähler variety X. We provide a classification of the R-symmetries in these models which allow the A-twist to be implemented, focusing on the case in which the gauge bundle is either a deformation of the tangent bundle of X or a deformation of a sub-bundle of the tangent bundle of X. Some anomaly-free examples are provided. The curvature constraint imposed by supersymmetry in these models when the superpotential is not holomorphic is reviewed. Constraints of this nature have been used to establish properties of analogues of pullbacks of Mathai–Quillen forms which arise in the correlation functions of the corresponding A-twisted or B-twisted heterotic Landau–Ginzburg models. The analogue most relevant to this paper is a deformation of the pullback of a Mathai–Quillen form. We discuss how this deformation may arise in the class of models studied in this paper. We then comment on how analogues of pullbacks of Mathai–Quillen forms not discussed in previous work may be obtained. Standard Mathai–Quillen formalism is reviewed in an appendix. We also include an appendix which discusses the deformation of the pullback of a Mathai–Quillen form.
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(This article belongs to the Collection High Energy Physics)
Open AccessCommunication
Amplitude and Phase Control of RF Pulse Using IQ Modulator to Improve Electron Beam Quality
by
, , , , , , , , , , , and
Particles 2023, 6(3), 739-745; https://doi.org/10.3390/particles6030046 - 18 Jul 2023
Abstract
A test-Accelerator as Coherent Terahertz Source (t-ACTS) has been under development at Tohoku University, in which an intense coherent terahertz radiation is generated from the short electron bunches. Velocity bunching scheme in a traveling wave accelerating structure is employed to generate the short
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A test-Accelerator as Coherent Terahertz Source (t-ACTS) has been under development at Tohoku University, in which an intense coherent terahertz radiation is generated from the short electron bunches. Velocity bunching scheme in a traveling wave accelerating structure is employed to generate the short electron bunches. The in-phase and quadrature (IQ) modulator and demodulator were installed to the low-level RF systems of t-ACTS linac to control and measure the amplitude and phase of RF power. The amplitude and phase of the RF power applied to an RF electron gun cavities and the accelerating structure are controlled to produce the electron bunches with a uniform and small momentum spread suitable for the velocity bunching. By installing the feed-forward control system using IQ modulators for the beam conditioning, we have successfully generated flat RF pulses and improved beam quality, including the energy spectrum of the beam. The details of feed-forward control system of the amplitude and phase using the IQ modulator and the beam experiments are presented in this paper.
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(This article belongs to the Special Issue Generation and Application of High-Power Radiation Sources)
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Pre/Post-Merger Consistency Test for Gravitational Signals from Binary Neutron Star Mergers
Particles 2023, 6(3), 731-738; https://doi.org/10.3390/particles6030045 - 14 Jul 2023
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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,
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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.
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Open AccessReview
Impact of Multiple Phase Transitions in Dense QCD on Compact Stars
Particles 2023, 6(3), 713-730; https://doi.org/10.3390/particles6030044 - 14 Jul 2023
Abstract
This review covers several recent developments in the physics of dense QCD with an emphasis on the impact of multiple phase transitions on astrophysical manifestations of compact stars. To motivate the multi-phase modeling of dense QCD and delineate the perspectives, we start with
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This review covers several recent developments in the physics of dense QCD with an emphasis on the impact of multiple phase transitions on astrophysical manifestations of compact stars. To motivate the multi-phase modeling of dense QCD and delineate the perspectives, we start with a discussion of the structure of its phase diagram and the arrangement of possible color-superconducting and other phases. It is conjectured that pair-correlated quark matter in -equilibrium is within the same universality class as spin-imbalanced cold atoms and the isospin asymmetrical nucleonic matter. This then implies the emergence of phases with broken space symmetries and tri-critical (Lifshitz) points. The beyond-mean-field structure of the quark propagator and its non-trivial implications are discussed in the cases of two- and three-flavor quark matter within the Eliashberg theory, which takes into account the frequency dependence (retardation) of the gap function. We then construct an equation of state (EoS) that extends the two-phase EoS of dense quark matter within the constant speed of sound parameterization by adding a conformal fluid with a speed of sound at densities , where is the saturation density. With this input, we construct static, spherically symmetrical compact hybrid stars in the mass–radius diagram, recover such features as the twins and triplets, and show that the transition to conformal fluid leads to the spiraling-in of the tracks in this diagram. Stars on the spirals are classically unstable with respect to the radial oscillations but can be stabilized if the conversion timescale between quark and nucleonic phases at their interface is larger than the oscillation period. Finally, we review the impact of a transition from high-temperature gapped to low-temperature gapless two-flavor phase on the thermal evolution of hybrid stars.
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(This article belongs to the Special Issue Strong Interactions in the Standard Model: Massless Bosons to Compact Stars)
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Open AccessArticle
Electron Energy Spectrometer for MIR-THz FEL Light Source at Chiang Mai University
Particles 2023, 6(3), 703-712; https://doi.org/10.3390/particles6030043 - 07 Jul 2023
Abstract
The linear accelerator system of the PBP-CMU Electron Linac Laboratory has been designed with the aim of generating free-electron lasers (FELs) in the mid-infrared (MIR) and terahertz (THz) regions. The quality of the radiation is strongly dependent on the properties of the electron
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The linear accelerator system of the PBP-CMU Electron Linac Laboratory has been designed with the aim of generating free-electron lasers (FELs) in the mid-infrared (MIR) and terahertz (THz) regions. The quality of the radiation is strongly dependent on the properties of the electron beam. Among the important beam parameters, the electron beam energy and energy spread are particularly important. To accurately measure the electron beam energy, the first dipole magnet in the bunch compressor system and the downstream screen station are employed as an energy spectrometer. The A Space Charge Tracking Algorithm (ASTRA) software is used for the design and optimization of this system. Simulation results demonstrate that the developed spectrometer is capable of accurately measuring the energy within the 5–25 MeV range. The screen station system is designed and constructed to have the ability to capture a beam size with a resolution of 0.1 mm per pixel. This resolution is achieved with a screen-to-camera distance of 1.2 m, which proves sufficient for precise energy measurement. The systematic error in energy measurement is found to be less than 10%, with a minimum energy spread of 0.4% achievable when the horizontal beam size remains below 3 mm.
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(This article belongs to the Special Issue Generation and Application of High-Power Radiation Sources)
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Open AccessArticle
Study of Coherent Smith–Purcell Radiation in the Terahertz Region Using Ultra-Short Electron Bunches
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, , , , , , , , and
Particles 2023, 6(3), 693-702; https://doi.org/10.3390/particles6030042 - 03 Jul 2023
Abstract
Smith–Purcell radiation (SPR) can be generated nondestructively, providing valuable applications in light sources and beam monitors. Coherent SPR is expected to enable single-shot measurements of very short bunch lengths on the fs scale. Since the reconstruction of the longitudinal bunch shape from the
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Smith–Purcell radiation (SPR) can be generated nondestructively, providing valuable applications in light sources and beam monitors. Coherent SPR is expected to enable single-shot measurements of very short bunch lengths on the fs scale. Since the reconstruction of the longitudinal bunch shape from the coherent SPR is based on the reliable SPR spectrum, a more detailed understanding of the properties of the radiation is important in this context. Employing a 100 fs ultrashort electron bunch at the t-ACTS test accelerator, the spectrum, angular distribution, and polarization of the produced coherent SPR were measured in the terahertz frequency region and compared with a model calculation. In addition to the widely known surface current model evaluation, the effect of the geometrical shading effect on induced currents on metal surfaces was evaluated using 3D numerical calculations. The obtained SPR characteristics are also presented. In the evaluation of the grating with a shallow blaze angle, it was found that the shading effect has a non-negligible effect on the generated SPR intensity; the measured angular distribution and polarization results were in good agreement with this result.
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(This article belongs to the Special Issue Generation and Application of High-Power Radiation Sources)
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Neutrino Spectrum and Energy Loss Rates Due to Weak Processes on Hot 56Fe in Pre-Supernova Environment
Particles 2023, 6(3), 682-692; https://doi.org/10.3390/particles6030041 - 28 Jun 2023
Abstract
Applying TQRPA calculations of Gamow–Teller strength functions in hot nuclei, we compute the (anti)neutrino spectra and energy loss rates arising from weak processes on hot Fe under pre-supernova conditions. We use a realistic pre-supernova model calculated by the stellar evolution code MESA.
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Applying TQRPA calculations of Gamow–Teller strength functions in hot nuclei, we compute the (anti)neutrino spectra and energy loss rates arising from weak processes on hot Fe under pre-supernova conditions. We use a realistic pre-supernova model calculated by the stellar evolution code MESA. Taking into account both charged and neutral current processes, we demonstrate that weak reactions with hot nuclei can produce high-energy (anti)neutrinos. We also show that, for hot nuclei, the energy loss via (anti)neutrino emission is significantly larger than that for nuclei in their ground state. It is found that the neutral current de-excitation via the -pair emission is presumably a dominant source of antineutrinos. In accordance with other studies, we confirm that the so-called single-state approximation for neutrino spectra might fail under certain pre-supernova conditions.
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(This article belongs to the Special Issue Infinite and Finite Nuclear Matter (INFINUM))
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Design and Beam Dynamic Studies of an Injector for a Compact THz Coherent Radiation Source
by
, , , , and
Particles 2023, 6(2), 674-681; https://doi.org/10.3390/particles6020040 - 16 Jun 2023
Abstract
An intense narrow-band terahertz (THz) radiation source has been designed to generate a broad tuning range of radiation frequencies between 0.5 THz and 5.0 THz. The THz radiation is produced when a short-bunch electron beam propagates through an undulator. To achieve high-power peak
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An intense narrow-band terahertz (THz) radiation source has been designed to generate a broad tuning range of radiation frequencies between 0.5 THz and 5.0 THz. The THz radiation is produced when a short-bunch electron beam propagates through an undulator. To achieve high-power peak radiation, the source requires high-brightness electron beams with low beam emittance and short bunch length. A proposed design for the photocathode RF gun used as the electron source is presented. The gun with high mode separation and high Q-factor can be achieved for producing a good beam quality. The beam dynamics of the injector have been preliminarily optimized using the software ASTRA and Elegant, investigating the impact of laser pulse shape on electron beam quality. The results of the beam dynamics studies are comprehensively discussed in this paper.
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(This article belongs to the Special Issue Generation and Application of High-Power Radiation Sources)
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Development of Type A Quadrupole Magnet for Siam Photon Source II
by
, , , , , , , and
Particles 2023, 6(2), 664-673; https://doi.org/10.3390/particles6020039 - 09 Jun 2023
Abstract
A prototype of a type A quadrupole magnet has been designed and manufactured for the 3 GeV storage ring of Siam Photon Source II, the second synchrotron light source in Thailand. The required quadrupole gradient is 51 T/m with the magnet effective length
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A prototype of a type A quadrupole magnet has been designed and manufactured for the 3 GeV storage ring of Siam Photon Source II, the second synchrotron light source in Thailand. The required quadrupole gradient is 51 T/m with the magnet effective length being 162 mm. Magnet modeling and magnetic field calculation were performed using Radia and Opera-3D. The bore radius of the magnet is 16 mm. The magnet will be operated at the excitation of 5544 A-turns. A mechanical analysis of the magnet structure was performed in SOLIDWORKS and ANSYS, where the maximum deformation of 0.003 mm was found at the magnet poles, and the first-mode natural frequency was higher than 100 Hz. The magnet yoke is made of AISI 1006 low-carbon steel with a fabrication tolerance of ±0.020 mm. Magnet coils are water-cooled and made of high-purity copper. The temperature rise of the coils was below 3.0 °C at the maximum excitation of 6664 A-turns, which is 20% above the operating point. Magnetic field measurement was carried out using the Hall probe technique. The measured magnetic field and coil temperature of the prototype show good agreement with the calculations.
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(This article belongs to the Special Issue Generation and Application of High-Power Radiation Sources)
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Density and Mass Function for Regular Rotating Electrically Charged Compact Objects Determined by Nonlinear Electrodynamics Minimally Coupled to Gravity
Particles 2023, 6(2), 647-663; https://doi.org/10.3390/particles6020038 - 06 Jun 2023
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We address the question of the electromagneticdensity and the mass function for regular rotating electrically charged compact objects as determined by dynamical equations of nonlinear electrodynamics minimally coupled to gravity. The rotating electrically charged compact objects are described by axially symmetric geometry, in
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We address the question of the electromagneticdensity and the mass function for regular rotating electrically charged compact objects as determined by dynamical equations of nonlinear electrodynamics minimally coupled to gravity. The rotating electrically charged compact objects are described by axially symmetric geometry, in which their electromagnetic fields are governed by four source-free equations for two independent field components of the electromagnetic tensor , with two constraints on the integration functions. An additional condition of compatibility of four dynamical equations for two independent field functions imposes the constraint on the Lagrange derivative , directly related to the electromagnetic density. As a result, the compatibility condition determines uniquely the generic form of the electromagnetic density and the mass function for regular rotating electrically charged compact objects.
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Open AccessArticle
The Particle-Tracking Simulation of a New Photocathode RF Gun in the Free-Electron Laser Facility, KU-FEL
Particles 2023, 6(2), 638-646; https://doi.org/10.3390/particles6020037 - 06 Jun 2023
Abstract
A project is underway that aims to generate attosecond pulses via high-harmonic generation in rare gases, driven by extremely short and highly intense pulses from free-electron-laser oscillators. For this purpose, it has been planned that a new photocathode RF gun, dedicated to high-bunch-charge
[...] Read more.
A project is underway that aims to generate attosecond pulses via high-harmonic generation in rare gases, driven by extremely short and highly intense pulses from free-electron-laser oscillators. For this purpose, it has been planned that a new photocathode RF gun, dedicated to high-bunch-charge operation, will be installed at the KU-FEL (Kyoto University Free Electron Laser) oscillator facility. In this study, RF guns with two different structures (1.6-cell and 1.4-cell) were compared, from the perspective of exploring the possibility of introducing bunch-interval modulation, which is important for achieving high extraction efficiency in the FEL oscillator. As a result, it was confirmed that the introduction of bunch-phase modulation would be possible only in the case of the 1.6-cell RF gun. After the structure of the RF gun was decided on, particle-tracking simulations were performed, to study the electron-beam parameters using the 1.6-cell RF gun and 1 nC bunch charge. The results showed that we could obtain the peak current of 1 kA without a large degradation of the other parameters.
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(This article belongs to the Special Issue Generation and Application of High-Power Radiation Sources)
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Toward the System Size Dependence of Anisotropic Flow in Heavy-Ion Collisions at
by
and
Particles 2023, 6(2), 622-637; https://doi.org/10.3390/particles6020036 - 02 Jun 2023
Abstract
The study of the high-density equation of state (EOS) and the search for a possible phase transition in dense baryonic matter is the main goal of beam energy scan programs with relativistic heavy ions at energies = 2–5 GeV. The
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The study of the high-density equation of state (EOS) and the search for a possible phase transition in dense baryonic matter is the main goal of beam energy scan programs with relativistic heavy ions at energies = 2–5 GeV. The most stringent constraints currently available on the high-density EOS of symmetric nuclear matter come from the present measurements of directed ( ) and elliptic flow ( ) signals of protons in Au + Au collisions. In this energy range, the anisotropic flow is strongly affected by the presence of cold spectators due to the sizable passage time. The system size dependence of anisotropic flow may help to study the participant–spectator contribution and improve our knowledge of the EOS of symmetric nuclear matter. In this work, we discuss the layout of the upgraded [email protected] experiment and the anticipated performance for differential anisotropic flow measurements of identified hadrons at Nuclotron energies: = 2.3–3.5 GeV.
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(This article belongs to the Special Issue Selected Papers from "Physics Performance Studies at FAIR and NICA")
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Testing the Paradigm of Nuclear Many-Body Theory
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Particles 2023, 6(2), 611-621; https://doi.org/10.3390/particles6020035 - 31 May 2023
Cited by 2
Abstract
Nuclear many-body theory is based on the tenet that nuclear systems can be accurately described as collections of point-like particles. This picture, while providing a remarkably accurate explanation of a wealth of measured properties of atomic nuclei, is bound to break down in
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Nuclear many-body theory is based on the tenet that nuclear systems can be accurately described as collections of point-like particles. This picture, while providing a remarkably accurate explanation of a wealth of measured properties of atomic nuclei, is bound to break down in the high-density regime, in which degrees of freedom other than protons and neutrons are expected to come into play. Valuable information on the validity of the description of dense nuclear matter in terms of nucleons, needed to firmly establish its limit of applicability, can be obtained from electron–nucleus scattering data at large momentum transfer and low energy transfer. The emergence of y-scaling in this kinematic region, unambiguously showing that the beam particles couple to high-momentum nucleons belonging to strongly correlated pairs, indicates that at densities as large as five times nuclear density—typical of the neutron star interior—nuclear matter largely behaves as a collection of nucleons.
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(This article belongs to the Special Issue 2022 Feature Papers by Particles’ Editorial Board Members)
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Parameters and Pulsation Constant of Cepheid
Particles 2023, 6(2), 595-610; https://doi.org/10.3390/particles6020034 - 26 May 2023
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The analysis of fifty empirical period-radius relations and forty-three empirical period-luminosity relations is performed for the Cepheids. It is found that most of these relations have significant systematic errors. A new metrological method is suggested to exclude these systematic errors using the new
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The analysis of fifty empirical period-radius relations and forty-three empirical period-luminosity relations is performed for the Cepheids. It is found that most of these relations have significant systematic errors. A new metrological method is suggested to exclude these systematic errors using the new empirical metrological relations and the empirical temperature scale of the various samples of the Cepheids. In this regard, the reliable relations between the mass, radius, effective surface temperature, luminosity, absolute magnitude on the one hand, and the pulsation period on the other hand, as well as the reliable dependence of the radius on the mass are determined for the Cepheids of types δ Cephei and δ Scuti from the Galaxy. These reliable relations permit us to accurately determine the empirical value of the pulsation constant for the Cepheids of both types for the first time. It is found that the pulsation constant very weakly depends on the pulsation period of the Cepheid, contrary to the known theoretical calculation. Hence, the Cepheids pulsate almost as a unified whole and homogeneous spherical body in wide ranges of a star’s mass and evolutionary state with an extremely inhomogeneous distribution of stellar substance over its volume. Therefore, it is first suggested that the pulsation of the Cepheid is, first of all, the pulsation of the almost unified whole and homogenous shell of its gravitational mass. This pulsation is triggered by well-known effects; for example, the local optical opacity of the stellar substance and overshooting, using the usual pulsation of the stellar substance.
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Open AccessReview
Mechanisms of Producing Primordial Black Holes and Their Evolution
Particles 2023, 6(2), 580-594; https://doi.org/10.3390/particles6020033 - 14 May 2023
Abstract
Primordial black holes have become a highly intriguing and captivating field of study in cosmology due to their potential theoretical and observational significance. This review delves into a variety of mechanisms that could give rise to PBHs and explores various methods for examining
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Primordial black holes have become a highly intriguing and captivating field of study in cosmology due to their potential theoretical and observational significance. This review delves into a variety of mechanisms that could give rise to PBHs and explores various methods for examining their evolution through mass accretion.
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(This article belongs to the Special Issue Beyond the Standard Models in Particle Physics and Cosmology)
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Centrality Determination in Heavy-Ion Collisions Based on Monte-Carlo Sampling of Spectator Fragments
by
Particles 2023, 6(2), 568-579; https://doi.org/10.3390/particles6020032 - 10 May 2023
Abstract
The size and evolution of the matter created in a relativistic heavy-ion collision strongly depend on collision geometry, defined by centrality. Experimentally the centrality of collisions can be characterized by the measured multiplicities of the produced particles at midrapidity or by the energy
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The size and evolution of the matter created in a relativistic heavy-ion collision strongly depend on collision geometry, defined by centrality. Experimentally the centrality of collisions can be characterized by the measured multiplicities of the produced particles at midrapidity or by the energy measured in the forward rapidity region, which is sensitive to the spectator fragments. This serves as a proxy for the true collision centrality, as defined by the impact parameter in the models of collisions. In this work, the procedure for centrality determination based on Monte-Carlo sampling of spectator fragments has been proposed. The validity of the procedure has been checked using the fully reconstructed DCM-QGSM-SMM model events and published data from the NA61/SHINE experiment.
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(This article belongs to the Special Issue Selected Papers from "Physics Performance Studies at FAIR and NICA")
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The van der Waals Hexaquark Chemical Potential in Dense Stellar Matter
Particles 2023, 6(2), 556-567; https://doi.org/10.3390/particles6020031 - 09 May 2023
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We explore the chemical potential of a QCD-motivated van der Waals (VDW) phase change model for the six-quark color-singlet, strangeness S = −2 particle known as the hexaquark with quark content (uuddss). The hexaquark may have internal structure, indicated by short range correlations
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We explore the chemical potential of a QCD-motivated van der Waals (VDW) phase change model for the six-quark color-singlet, strangeness S = −2 particle known as the hexaquark with quark content (uuddss). The hexaquark may have internal structure, indicated by short range correlations that allow for non-color-singlet diquark and triquark configurations whose interactions will change the magnitude of the chemical potential. In the multicomponent VDW Equation of State (EoS), the quark-quark particle interaction terms are sensitive to the QCD color factor, causing the pairing of these terms to give different interaction strengths for their respective contributions to the chemical potential. This results in a critical temperature near 163 MeV for the color-singlet states and tens of MeV below this for various mixed diquark and triquark states. The VDW chemical potential is also sensitive to the number density, leading to chemical potential isotherms that exhibit spinodal extrema, which also depend upon the internal hexaquark configurations. These extrema determine regions of metastability for the mixed states near the critical point. We use this chemical potential with the chemical potential-modified TOV equations to investigate the properties of hexaquark formation in cold compact stellar cores in beta equilibrium. We find thresholds for hexaquark layers and changes in maximum mass values that are consistent with observations from high mass compact stellar objects such as PSR 09043 + 10 and GW 190814. In general, we find that the VDW-TOV model has an upper stability mass and radius bound for a chemical potential of 1340 MeV with a compactness of C~0.2.
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Probing the Hot QCD Matter via Quarkonia at the Next-Generation Heavy-Ion Experiment at LHC
Particles 2023, 6(2), 546-555; https://doi.org/10.3390/particles6020030 - 02 May 2023
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Quarkonia represent one of the most valuable probes of the deconfined quark–gluon hot medium since the very first experimental studies with ultrarelativistic heavy-ion collisions. A significant step forward in characterizing the QCD matter via systematic studies of quarkonia production will be performed by
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Quarkonia represent one of the most valuable probes of the deconfined quark–gluon hot medium since the very first experimental studies with ultrarelativistic heavy-ion collisions. A significant step forward in characterizing the QCD matter via systematic studies of quarkonia production will be performed by the next-generation heavy-ion experiment ALICE 3, a successor of the ongoing ALICE experiment at the Large Hadron Collider. The new advanced detector of ALICE 3 will allow for exploring the production of S- and P-state quarkonia at high statistics, at low and moderate transverse momenta ranges. The performance of ALICE 3 for quarkonia measurements and the requirements for the detectors are discussed.
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Open AccessReview
Several Topics on Transverse Momentum-Dependent Fragmentation Functions
Particles 2023, 6(2), 515-545; https://doi.org/10.3390/particles6020029 - 27 Apr 2023
Abstract
The hadronization of a high-energy parton is described by fragmentation functions which are introduced through QCD factorizations. While the hadronization mechanism per se remains uknown, fragmentation functions can still be investigated qualitatively and quantitatively. The qualitative study mainly concentrates on extracting genuine features
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The hadronization of a high-energy parton is described by fragmentation functions which are introduced through QCD factorizations. While the hadronization mechanism per se remains uknown, fragmentation functions can still be investigated qualitatively and quantitatively. The qualitative study mainly concentrates on extracting genuine features based on the operator definition in quantum field theory. The quantitative research focuses on describing a variety of experimental data employing the fragmentation function given by the parameterizations or model calculations. With the foundation of the transverse-momentum-dependent factorization, the QCD evolution of leading twist transverse-momentum-dependent fragmentation functions has also been established. In addition, the universality of fragmentation functions has been proven, albeit model-dependently, so that it is possible to perform a global analysis of experimental data in different high-energy reactions. The collective efforts may eventually reveal important information hidden in the shadow of nonperturbative physics. This review covers the following topics: transverse-momentum-dependent factorization and the corresponding QCD evolution, spin-dependent fragmentation functions at leading and higher twists, several experimental measurements and corresponding phenomenological studies, and some model calculations.
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(This article belongs to the Special Issue Strong Interactions in the Standard Model: Massless Bosons to Compact Stars)
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Centrality Selection Effect on Elliptic Flow Measurements in Relativistic Heavy-Ion Collisions at NICA Energies
Particles 2023, 6(2), 497-514; https://doi.org/10.3390/particles6020028 - 26 Apr 2023
Abstract
The elliptic flow ( ) of produced particles is one of the important observables sensitive to the transport properties of the strongly interacting matter created in relativistic heavy-ion collisions. Detailed differential measurements of are also foreseen in the future
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The elliptic flow ( ) of produced particles is one of the important observables sensitive to the transport properties of the strongly interacting matter created in relativistic heavy-ion collisions. Detailed differential measurements of are also foreseen in the future Multi-Purpose Detector (MPD) experiment at the Nuclotron based Ion Collider fAcility (NICA) at collision energies = 4–11 GeV. Elliptic flow strongly depends on collision geometry, defined by the impact parameter b. Usually b is an input to theoretical calculations and can be deduced from experimental observables in the final state using the centrality procedure. In this work, we investigate the influence of the choice of centrality procedure on the elliptic flow measurements at NICA energies.
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(This article belongs to the Special Issue Selected Papers from "Physics Performance Studies at FAIR and NICA")
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Nanotechnological Advancement in Biopolymer Functionalization
Topic Editors: Pritam Kumar Dikshit, Vijayanand S. Moholkar, Mamata Singhvi, Suchada Chanprateep NapathornDeadline: 20 December 2023
Conferences
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Particles
Infinite and Finite Nuclear Matter (INFINUM)
Guest Editors: Evgeni Kolomeitsev, Nikolai Antonenko, David Blaschke, Victor Braguta, Isaac VidañaDeadline: 31 August 2023
Special Issue in
Particles
Selected Papers from “Testing Gravity 2023”
Guest Editors: Andrei V. Frolov, Makoto Fujiwara, Levon Pogosian, Dimitrios Psaltis, Douglas Scott, Alessandra SilvestriDeadline: 1 October 2023
Special Issue in
Particles
Selected Papers from “Dark Matter and Stars: Multi-Messenger Probes of Dark Matter and Modified Gravity”
Guest Editors: Ilídio Lopes, Violetta Sagun, Laura SagunskiDeadline: 31 October 2023
Special Issue in
Particles
Parton Distribution Functions at a Crossroad
Guest Editors: Zhu-Fang Cui, Craig RobertsDeadline: 22 December 2023
Topical Collections
Topical Collection in
Particles
The 50 Years of Relativistic Heavy Ion Experiments Using Accelerator Systems
Collection Editor: Alexandru Jipa
Topical Collection in
Particles
Dark Matter and New Physics of Hidden Particles
Collection Editors: Valery E. Lyubovitskij, Dmitry V. Kirpichnikov, Alexey S. Zhevlakov