Inhaled particles最新文献_第5页

Λ and Λ¯ Freeze-Out Distributions and Global Polarizations in Au+Au Collisions Λ和Λ¯Au+Au碰撞中的冻结分布和全局极化

Inhaled particles Pub Date : 2023-02-27 DOI: 10.3390/particles6010019

Nikita Tsegelnik, E. Kolomeitsev, V. Voronyuk

{"title":"Λ and Λ¯ Freeze-Out Distributions and Global Polarizations in Au+Au Collisions","authors":"Nikita Tsegelnik, E. Kolomeitsev, V. Voronyuk","doi":"10.3390/particles6010019","DOIUrl":"https://doi.org/10.3390/particles6010019","url":null,"abstract":"The gold–gold collisions at sNN=7.7 and 11.5 GeV are simulated within the PHSD transport model. In each collision event, the spectator nucleons are separated and the fluidization procedure for the participants is performed. The local velocities are determined in the Landau frame and the kinematic and thermal vorticity fields are evaluated. We analyze the thermodynamic properties of the cells where Λs and Λ¯s were born or had their last interaction. Such cells contribute to the formation of the observed global polarization of hyperons induced by the thermal vorticity of the medium. The Λ¯ polarization signal is found to be mainly determined by hot, dense, and highly vortical cells at the earlier stage of the collision, whereas the Λ polarization signal is accumulated over the longer time and includes cells with lower vorticity. The calculated global polarizations for both Λs and Λ¯s agree well with the experimental finding by the STAR collaboration at energy sNN=11.5 GeV. For collisions at sNN=7.7 GeV, we can reproduce the STAR data for Λ hyperons, but significantly underpredict the observed global polarization of Λ¯. Furthermore, we consider the centrality dependence of the hyperon polarization in collisions at 7.7 GeV. It increases with an increase of centrality, reaches a maximum at 65–75% and then starts decreasing rapidly for peripheral collisions.","PeriodicalId":75932,"journal":{"name":"Inhaled particles","volume":"73 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82669675","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: 1

Feasibility Studies for the Measurement of Open-Charm Mesons at ALICE-3 Using Decay Channels with Neutral Mesons and Photons in the Final State 在ALICE-3上用中性介子和最终态光子衰变通道测量开粲介子的可行性研究

Inhaled particles Pub Date : 2023-02-17 DOI: 10.3390/particles6010018

M. Malaev, V. Riabov

{"title":"Feasibility Studies for the Measurement of Open-Charm Mesons at ALICE-3 Using Decay Channels with Neutral Mesons and Photons in the Final State","authors":"M. Malaev, V. Riabov","doi":"10.3390/particles6010018","DOIUrl":"https://doi.org/10.3390/particles6010018","url":null,"abstract":"ALICE-3 is being designed as a next-generation heavy-ion experiment to be operated at the high-luminosity Large Hadron Collider. With luminosities higher by a factor of fifty, ALICE-3 will be able to study5 properties of quark–gluon matter with probes and precision which were previously unavailable due to small cross sections, high background levels, and insufficient detector sensitivity. In particular, the properties of hot and dense QCD matter will be studied by measuring production cross sections, flow coefficients, azimuthal angular correlations and nuclear modification factors for open-charm hadrons. In this contribution, we present the results of feasibility studies for the measurement of ground and excited states of open-charm mesons in decay channels D0 → K− + π+ + π0, D*(2007)0 → D0 + γ and D*(2010)± → D0 + π± in pp, p-Pb and Pb-Pb collisions at LHC energies using the ALICE-3 experimental setup. We formulate the main requirements for the selection of particles and their combinations to ensure reliable signal extraction in a wide transverse momentum range and estimate the minimum size of the required data samples. The results obtained are also compared to previous findings for the open-charm measurements in different decay channels.","PeriodicalId":75932,"journal":{"name":"Inhaled particles","volume":"90 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75371884","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

Long-Lived Particles Anomaly Detection with Parametrized Quantum Circuits 参数化量子电路的长寿命粒子异常检测

Inhaled particles Pub Date : 2023-02-13 DOI: 10.3390/particles6010016

Simone Bordoni, Denis Stanev, Tommaso Santantonio, S. Giagu

{"title":"Long-Lived Particles Anomaly Detection with Parametrized Quantum Circuits","authors":"Simone Bordoni, Denis Stanev, Tommaso Santantonio, S. Giagu","doi":"10.3390/particles6010016","DOIUrl":"https://doi.org/10.3390/particles6010016","url":null,"abstract":"We investigate the possibility to apply quantum machine learning techniques for data analysis, with particular regard to an interesting use-case in high-energy physics. We propose an anomaly detection algorithm based on a parametrized quantum circuit. This algorithm was trained on a classical computer and tested with simulations as well as on real quantum hardware. Tests on NISQ devices were performed with IBM quantum computers. For the execution on quantum hardware, specific hardware-driven adaptations were devised and implemented. The quantum anomaly detection algorithm was able to detect simple anomalies such as different characters in handwritten digits as well as more complex structures such as anomalous patterns in the particle detectors produced by the decay products of long-lived particles produced at a collider experiment. For the high-energy physics application, the performance was estimated in simulation only, as the quantum circuit was not simple enough to be executed on the available quantum hardware platform. This work demonstrates that it is possible to perform anomaly detection with quantum algorithms; however, as an amplitude encoding of classical data is required for the task, due to the noise level in the available quantum hardware platform, the current implementation cannot outperform classic anomaly detection algorithms based on deep neural networks.","PeriodicalId":75932,"journal":{"name":"Inhaled particles","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73700339","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: 4

Generalised Parton Distributions in Continuum Schwinger Methods: Progresses, Opportunities and Challenges 连续统Schwinger方法中的广义部子分布:进展、机遇和挑战

Inhaled particles Pub Date : 2023-02-08 DOI: 10.3390/particles6010015

Cédric Mezrag

引用次数: 5

Λ Polarization and Vortex Rings in Heavy-Ion Collisions at NICA Energies Λ NICA能量下重离子碰撞中的极化和漩涡环

Inhaled particles Pub Date : 2023-02-06 DOI: 10.3390/particles6010014

Y. Ivanov, Alexei A. Soldatov

{"title":"Λ Polarization and Vortex Rings in Heavy-Ion Collisions at NICA Energies","authors":"Y. Ivanov, Alexei A. Soldatov","doi":"10.3390/particles6010014","DOIUrl":"https://doi.org/10.3390/particles6010014","url":null,"abstract":"We review recent studies of vortical motion and the resulting polarization of Λ hyperons in heavy-ion collisions at NICA energies, in particular, within the model of three-fluid dynamics (3FD). This includes predictions of the global Λ polarization and ring structures that appear in Au+Au collisions. The global Λ polarization in Au+Au collisions is calculated, including its rapidity and centrality dependence. The contributions of the thermal vorticity and meson-field term (proposed by Csernai, Kapusta, and Welle) to the global polarization are considered. The results are compared with data from recent STAR and HADES experiments. It is predicted that the polarization maximum is reached at sNN≈ 3 GeV if the measurements are performed with the same acceptance. It is demonstrated that a pair of vortex rings are formed, one at forward rapidities and another at backward rapidities, in ultra-central Au+Au collisions at sNN> 4 GeV. The vortex rings carry information about the early stage of the collision, in particular, the stopping of baryons. It is shown that these rings can be detected by measuring the ring observable RΛ, even in the midrapidity region at sNN= 5–20 GeV. At forward/backward rapidities, the RΛ signal is expected to be stronger. The possibility of observing the vortex-ring signal against the background of non-collective transverse polarization is discussed.","PeriodicalId":75932,"journal":{"name":"Inhaled particles","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90922933","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

Bayesian Exploration of Phenomenological EoS of Neutron/Hybrid Stars with Recent Observations 中子星/混合星现象学EoS的贝叶斯探索与最新观测

Inhaled particles Pub Date : 2023-02-02 DOI: 10.3390/particles6010011

E. Chimanski, R. Lobato, A. R. Gonçalves, C. Bertulani

{"title":"Bayesian Exploration of Phenomenological EoS of Neutron/Hybrid Stars with Recent Observations","authors":"E. Chimanski, R. Lobato, A. R. Gonçalves, C. Bertulani","doi":"10.3390/particles6010011","DOIUrl":"https://doi.org/10.3390/particles6010011","url":null,"abstract":"The description of the stellar interior of compact stars remains as a big challenge for the nuclear astrophysics community. The consolidated knowledge is restricted to density regions around the saturation of hadronic matter ρ0=2.8×1014gcm−3, regimes where our nuclear models are successfully applied. As one moves towards higher densities and extreme conditions up to the quark/gluons deconfinement, little can be said about the microphysics of the equation of state (EoS). Here, we employ a Markov Chain Monte Carlo (MCMC) strategy to access the variability at high density regions of polytropic piecewise models for neutron star (NS) EoS or possible hybrid stars, i.e., a NS with a small quark-matter core. With a fixed description of the hadronic matter for low density, below the nuclear saturation density, we explore a variety of models for the high density regimes leading to stellar masses near to 2.5M⊙, in accordance with the observations of massive pulsars. The models are constrained, including the observation of the merger of neutrons stars from VIRGO-LIGO and with the pulsar observed by NICER. In addition, we also discuss the possibility of the use of a Bayesian power regression model with heteroscedastic error. The set of EoS from the Laser Interferometer Gravitational-Wave Observatory (LIGO) was used as input and treated as the data set for the testing case.","PeriodicalId":75932,"journal":{"name":"Inhaled particles","volume":"117 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82314883","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: 1

Masses of Compact (Neutron) Stars with Distinguished Cores 具有不同核心的致密(中子星)的质量

Inhaled particles Pub Date : 2023-02-02 DOI: 10.3390/particles6010012

R. Zöllner, M. Ding, B. Kämpfer

引用次数: 0

Charge Asymmetry of Muons Generated in a Muon Generator from Ultra-Dense Hydrogen D(0) and p(0) 超致密氢产生μ子的电荷不对称性D(0)和p(0)

Inhaled particles Pub Date : 2023-01-30 DOI: 10.3390/particles6010010

L. Holmlid

{"title":"Charge Asymmetry of Muons Generated in a Muon Generator from Ultra-Dense Hydrogen D(0) and p(0)","authors":"L. Holmlid","doi":"10.3390/particles6010010","DOIUrl":"https://doi.org/10.3390/particles6010010","url":null,"abstract":"Laser-induced nuclear reactions in ultra-dense hydrogen H(0) (review in Physica Scripta 2019) create mesons (kaons and pions). These mesons decay mainly to muons. The muons created are useful (patented source) for the muon-induced fusion process. The sign of the muons from the source depends on the initial baryons used. With D(0) (ultra-dense deuterium) the source produces mainly positive muons and with p(0) (ultra-dense protium) the source produces mainly negative muons. Negative muons are required for muon-induced fusion. This charge asymmetry was reported earlier, and has now been confirmed by experiments with a coil current transformer as the beam detector. The current coil detector would give no signal from the muons if charge symmetry existed. The charge asymmetry could indicate unknown processes, for example, caused by the different annihilation processes in D(0) and p(0). The conclusions of a new analysis of the results are presented here. Using D(0) in the muon source, the asymmetry is likely due to the capture of µ- in D atoms and D2 molecules. This leads to emission of excess µ+ from D(0). With p(0) in the muon source, the capture rate of µ- is lower than in D(0). The emitted number of µ+ will be decreased by the reaction between µ+ and the surrounding abundant electrons, forming neutral muonium particles. This effect decreases the amount of emitted µ+ for both p(0) and D(0), and it is proposed to be the main reason for a larger fraction of emitted µ- in the case of p(0). Thus, there is no dominant emission of negative muons which would violate charge conservation.","PeriodicalId":75932,"journal":{"name":"Inhaled particles","volume":"63 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88366933","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: 1

Direct Photon Production in Heavy-Ion Collisions: Theory and Experiment 重离子碰撞中直接光子的产生:理论与实验

Inhaled particles Pub Date : 2023-01-30 DOI: 10.3390/particles6010009

D. Blau, D. Peresunko

{"title":"Direct Photon Production in Heavy-Ion Collisions: Theory and Experiment","authors":"D. Blau, D. Peresunko","doi":"10.3390/particles6010009","DOIUrl":"https://doi.org/10.3390/particles6010009","url":null,"abstract":"Direct photons provide a possibility to test properties of hot matter created in proton–proton (pp), proton–nucleus (p–A) or nucleus–nucleus (A–A) collisions. As they are created in charged particles’ scatterings and freely escape the hot region, they provide a tool to test all stages of the collision: the scattering of the partons of incoming nucleons, pre-equilibrium evolution and collective expansion of hot quark–gluon matter created in nucleus–nucleus collisions. Comparing direct photon production in pp, p–A and A–A collisions, one can check the scaling with the number of binary collisions expected at a high transverse momentum range and obtain insight into the hot and cold hadronic matter properties with soft photons. The collective elliptic flow of direct photons is a unique possibility to trace the collective flow formation and space–time evolution of the fireball. We review the experimental results on direct photon production in pp, p–A and A–A collisions at the Super Proton Synchroton (SPS), the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) energies and discuss an agreement of theoretical predictions with measurements. Finally, we present predictions of direct photon spectra and collective flow for lower energy collisions expected at the Nuclotron-based Ion Collider fAcility (NICA) and the Facility for Antiproton and Ion Research (FAIR).","PeriodicalId":75932,"journal":{"name":"Inhaled particles","volume":"76 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88972246","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

Pre/Post-Merger Consistency Test for Gravitational Signals from Binary Neutron Star Mergers 双中子星并合重力信号前后一致性检验

Inhaled particles Pub Date : 2023-01-23 DOI: 10.3390/particles6030045

M. Breschi, G. Carullo, S. Bernuzzi

{"title":"Pre/Post-Merger Consistency Test for Gravitational Signals from Binary Neutron Star Mergers","authors":"M. Breschi, G. Carullo, S. Bernuzzi","doi":"10.3390/particles6030045","DOIUrl":"https://doi.org/10.3390/particles6030045","url":null,"abstract":"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.","PeriodicalId":75932,"journal":{"name":"Inhaled particles","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75322471","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: 2