Particles最新文献

Neutron Star–Dark Matter Admixed Objects in the Mass Gap Region 质量差距区域的中子星-暗物质混合天体

Particles Pub Date : 2024-08-08 DOI: 10.3390/particles7030040

Michael Vikiaris

{"title":"Neutron Star–Dark Matter Admixed Objects in the Mass Gap Region","authors":"Michael Vikiaris","doi":"10.3390/particles7030040","DOIUrl":"https://doi.org/10.3390/particles7030040","url":null,"abstract":"To this day, the nature of dark matter (DM) remains elusive despite all our efforts. This type of matter has not been directly observed, so we infer its gravitational effect. Since galaxies and supermassive objects like these are most likely to contain DM, we assume that dense objects such as neutron stars (NSs) are also likely to host DM. The NS is considered the best natural laboratory for testing theories and collecting observational data. We mainly focus on two types of DM particles, fermions and bosons, with a mass range of [0.01–1.5] GeV and repulsive interactions of about [10−4–10−1] MeV−1. Using a two-fluid model to solve the TOV equations, we find stable configurations that span hundreds of kilometers and weigh tens or even hundreds of solar masses. To visualize results, we think of a giant invisible compact DM object and the NS in the center as the core, the only visible part. Stability criteria are met for these configurations, so collapsing into a black hole is unlikely. We go further and use this work for smaller formations that exist inside the mysterious Mass Gap. We also find stable configurations of 3–4 solar masses, with NS-DM mixing capable of describing the mass gap. Regardless, the present theoretical prediction, if combined with corresponding observations, could shed light on the existence of DM and even more on its fundamental properties.","PeriodicalId":512239,"journal":{"name":"Particles","volume":"15 4","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141926296","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

On the Energy Budget of Quarks and Hadrons, Their Inconspicuous “Strong Charge”, and the Impact of Coulomb Repulsion on the Charged Ground States 夸克和中子的能量预算、它们不明显的 "强电荷 "以及库仑斥力对带电基态的影响

Particles Pub Date : 2024-07-26 DOI: 10.3390/particles7030038

D. Christodoulou, D. Kazanas

{"title":"On the Energy Budget of Quarks and Hadrons, Their Inconspicuous “Strong Charge”, and the Impact of Coulomb Repulsion on the Charged Ground States","authors":"D. Christodoulou, D. Kazanas","doi":"10.3390/particles7030038","DOIUrl":"https://doi.org/10.3390/particles7030038","url":null,"abstract":"We review and meta-analyze particle data and properties of hadrons with measured rest masses. The results of our study are summarized as follows. (1) The strong-force suppression of the repulsive Coulomb forces between quarks is sufficient to explain the differences between mass deficits in nucleons and pions (and only them), the ground states with the longest known mean lifetimes; (2) unlike mass deficits, the excitations in rest masses of all particle groups are effectively quantized, but the rules are different in baryons and mesons; (3) the strong field is aware of the extra factor of ϑe=2 in the charges (Q) of the positively charged quarks; (4) mass deficits incorporate contributions proportional to the mass of each valence quark; (5) the scaling factor of these contributions is the same for each quark in each group of particles, provided that the factor ϑe=2 is taken into account; (6) besides hypercharge (Y), the much lesser-known “strong charge” (Q′=Y−Q) is very useful in SU(3) in describing properties of particles located along the right-leaning sides and diagonals of the weight diagrams; (7) strong decays in which Q′ is conserved are differentiated from weak decays, even for the same particle; and (8) the energy diagrams of (anti)quark transitions indicate the origin of CP violation.","PeriodicalId":512239,"journal":{"name":"Particles","volume":"31 11","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141800907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Unruh Entropy with Exponential Energy Distribution for a Spherically Symmetric Source 球形对称源的指数能量分布的 Unruh 熵

Particles Pub Date : 2024-07-22 DOI: 10.3390/particles7030036

M. Teslyk, L. Bravina, E. Zabrodin

引用次数: 0

New Physics Opportunities at the DUNE Near Detector DUNE 近探测器的新物理机遇

Particles Pub Date : 2024-07-15 DOI: 10.3390/particles7030035

P. Melas, D. Papoulias, N. Saoulidou

引用次数: 0

Transforming DIY Geiger Counter Kits into Muon Detectors for Education and Scientific Exploration 将 DIY 盖革计数器套件改造成用于教育和科学探索的μ介子探测器

Particles Pub Date : 2024-07-12 DOI: 10.3390/particles7030034

Marco Arcani, D. Liguori, Andrea Frassà, Altea Renata Maria Nemolato, Omar Del Monte, Cesare Guaita

{"title":"Transforming DIY Geiger Counter Kits into Muon Detectors for Education and Scientific Exploration","authors":"Marco Arcani, D. Liguori, Andrea Frassà, Altea Renata Maria Nemolato, Omar Del Monte, Cesare Guaita","doi":"10.3390/particles7030034","DOIUrl":"https://doi.org/10.3390/particles7030034","url":null,"abstract":"Any Geiger counter can be used as an effective cosmic ray detector on its own. In fact, it is known that even in the absence of a radioactive source, the instrument detects what is known as background radiation, which consists of various types of ionizing particles present in the environment. Remarkably, it is estimated that up to 15% of this background radiation is attributable to cosmic rays, high-energy particles originating from outer space. The remaining radiation detected by the Geiger counter originates from terrestrial sources, such as natural radioactivity in the ground and in the air. The main goal of this project is to build a muon detector for scientific and educational purposes using two commercial DIY Geiger counter kits and just a few additional components. To identify cosmic radiation from terrestrial radiation and improve the accuracy of cosmic ray measurements, the use of a coincident circuit is essential. This coincident circuit was introduced in cosmic ray physics by Walther Bothe and Bruno Rossi in the early 1930s and allows for the detection of a subatomic particle passing through two or more sensors, thereby reducing false positives and enhancing the reliability of cosmic ray detection. The following idea is an alternative replica of our AMD5 detectors, instruments that we have been using for years to teach and perform scientific experiments in the cosmic ray field under the umbrella of the ADA project (2023 Particles, Arcani et al.). The resulting device, named AMD5ALI, offers a reliable and inexpensive solution for the same goal, making it a valuable tool for both educational purposes and scientific surveys. Practical applications range from cosmic ray physics to radioactivity, including the relationship between cosmic ray flux and meteorology, the zenithal effect, the Regener–Pfotzer curve in the atmosphere, and the anti-correlation of cosmic particle intensity with solar activity.","PeriodicalId":512239,"journal":{"name":"Particles","volume":"58 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141653375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A Multiple Scattering-Based Technique for Isotopic Identification in Cosmic Rays 基于多重散射的宇宙射线同位素鉴定技术

Particles Pub Date : 2024-05-02 DOI: 10.3390/particles7020027

Francesco Dimiccoli, F. Follega

引用次数: 0

Scales and Hierarchies: Planckian Signature in Standard Model 尺度与层次：标准模型中的普朗克特征

Particles Pub Date : 2024-04-22 DOI: 10.3390/particles7020025

Davide Fiscaletti, I. Licata

引用次数: 0

Feature Selection Techniques for CR Isotope Identification with the AMS-02 Experiment in Space 利用 AMS-02 太空实验识别 CR 同位素的特征选择技术

Particles Pub Date : 2024-04-20 DOI: 10.3390/particles7020024

Marta Borchiellini, Leandro Mano, Fernando Barão, Manuela Vecchi

{"title":"Feature Selection Techniques for CR Isotope Identification with the AMS-02 Experiment in Space","authors":"Marta Borchiellini, Leandro Mano, Fernando Barão, Manuela Vecchi","doi":"10.3390/particles7020024","DOIUrl":"https://doi.org/10.3390/particles7020024","url":null,"abstract":"Isotopic composition measurements of singly charged cosmic rays (CR) provide essential insights into CR transport in the Galaxy. The Alpha Magnetic Spectrometer (AMS-02) can identify singly charged isotopes up to about 10 GeV/n. However, their identification presents challenges due to the small abundance of CR deuterons compared to the proton background. In particular, a high accuracy for the velocity measured by a ring-imaging Cherenkov detector (RICH) is needed to achieve a good isotopic mass separation over a wide range of energies. The velocity measurement with the RICH is particularly challenging for Z=1 isotopes due to the low number of photons produced in the Cherenkov rings. This faint signal is easily disrupted by noisy hits leading to a misreconstruction of the particles’ ring. Hence, an efficient background reduction process is needed to ensure the quality of the reconstructed Cherenkov rings and provide a correct measurement of the particles’ velocity. Machine learning methods, particularly boosted decision trees, are well suited for this task, but their performance relies on the choice of the features needed for their training phase. While physics-driven feature selection methods based on the knowledge of the detector are often used, machine learning algorithms for automated feature selection can provide a helpful alternative that optimises the classification method’s performance. We compare five algorithms for selecting the feature samples for RICH background reduction, achieving the best results with the Random Forest method. We also test its performance against the physics-driven selection method, obtaining better results.","PeriodicalId":512239,"journal":{"name":"Particles","volume":" 1087","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140682149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Correction: Teslyk et al. Unruh Effect and Information Entropy Approach. Particles 2022, 5, 157–170 更正：Teslyk et al. Unruh Effect and Information Entropy Approach.Particles 2022, 5, 157-170

Particles Pub Date : 2024-04-18 DOI: 10.3390/particles7020023

M. Teslyk, L. Bravina, E. Zabrodin

引用次数: 0

Characterization of RF System for MIR/THz Free Electron Lasers at Chiang Mai University 清迈大学用于 MIR/THz 自由电子激光器的射频系统特性分析

Particles Pub Date : 2024-04-11 DOI: 10.3390/particles7020021

P. Kitisri, J. Saisut, S. Rimjaem

{"title":"Characterization of RF System for MIR/THz Free Electron Lasers at Chiang Mai University","authors":"P. Kitisri, J. Saisut, S. Rimjaem","doi":"10.3390/particles7020021","DOIUrl":"https://doi.org/10.3390/particles7020021","url":null,"abstract":"The establishment of the mid-infrared and terahertz free-electron laser (MIR/THz FEL) facility is ongoing at the PBP-CMU Electron Linac Laboratory (PCELL) in Chiang Mai University. The facility utilizes an S-band radio-frequency (RF) gun and a linear accelerator (linac) to generate and accelerate electron bunches. These electron bunches are accelerated in the RF gun and the linac using RF pulses with a frequency of 2856 MHz. Measuring the RF properties becomes essential, as the RF pulse information can be utilized to estimate the electron beam properties. To achieve the measurement results, we employed an RF measurement system comprising directional couplers, coaxial cables, attenuators, a crystal detector, and an oscilloscope. Prior to conducting measurements, the crystal detector and RF equipment were calibrated and characterized to ensure precise and reliable results. The electron beam energy estimation using the measured RF power was compared with the measured beam energies. The gun and the linac were operated with an absorbed RF power of 1.52 MW and an input power of 1.92 MW, respectively. The estimated electron beam energies were found to be 2.18 MeV and 15.0 MeV, respectively, closely aligning with the measured beam energies of 2.1 MeV and 14.0 MeV after the gun and linac acceleration. These consistent energy values support the reliability of our RF power measurement system and procedure.","PeriodicalId":512239,"journal":{"name":"Particles","volume":"21 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140714328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0