Astroparticle Physics最新文献

{"title":"Tensor fluctuations in the early universe","authors":"F. Melia","doi":"10.1016/j.astropartphys.2023.102876","DOIUrl":"10.1016/j.astropartphys.2023.102876","url":null,"abstract":"<div><p><span><span>In standard inflationary cosmology, scalar and tensor perturbations grew as the Universe expanded and froze when their wavelengths exceeded the Hubble horizon, producing a tell-tale signature in the fluctuation spectrum and amplitude of the cosmic microwave background (CMB). But there are now very good reasons to examine whether structure formation could also have begun via the seeding of </span>quantum fluctuations in a non-inflationary field. In this </span><em>Letter</em><span>, we study and compare the scalar and tensor modes produced in these two scenarios, and demonstrate that upcoming observations to measure the B-mode polarization of the CMB may be able to differentiate between them. Whereas both scalar and tensor modes should be observable if the field was inflationary, only scalar modes would be present in the CMB if it were not. Should gravity be purely classical, however, the tensor modes would have avoided canonical quantization in all cases, resulting in unmeasurably weak gravitational waves. A non-detection of B-mode polarization would thus not completely rule out inflation.</span></p></div>","PeriodicalId":55439,"journal":{"name":"Astroparticle Physics","volume":"152 ","pages":"Article 102876"},"PeriodicalIF":3.5,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48310613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of cosmogenic activation above ground for the DarkSide-20k experiment","authors":"A. Elersich ,&nbsp;P. Agnes ,&nbsp;I. Ahmad ,&nbsp;S. Albergo ,&nbsp;I.F.M. Albuquerque ,&nbsp;T. Alexander ,&nbsp;A.K. Alton ,&nbsp;P. Amaudruz ,&nbsp;M. Atzori Corona ,&nbsp;M. Ave ,&nbsp;I.Ch. Avetisov ,&nbsp;O. Azzolini ,&nbsp;H.O. Back ,&nbsp;Z. Balmforth ,&nbsp;A. Barrado-Olmedo ,&nbsp;P. Barrillon ,&nbsp;A. Basco ,&nbsp;G. Batignani ,&nbsp;V. Bocci ,&nbsp;W.M. Bonivento ,&nbsp;M.P. Zykova","doi":"10.1016/j.astropartphys.2023.102878","DOIUrl":"https://doi.org/10.1016/j.astropartphys.2023.102878","url":null,"abstract":"<div><p>The activation of materials due to exposure to cosmic rays may become an important background source for experiments investigating rare event phenomena. DarkSide-20k, currently under construction at the Laboratori Nazionali del Gran Sasso, is a direct detection experiment for galactic dark matter particles, using a two-phase liquid-argon Time Projection Chamber (TPC) filled with 49.7 tonnes (active mass) of Underground Argon (UAr) depleted in ³⁹Ar. Despite the outstanding capability of discriminating <span><math><mi>γ</mi></math></span>/<span><math><mi>β</mi></math></span> background in argon TPCs, this background must be considered because of induced dead time or accidental coincidences mimicking dark-matter signals and it is relevant for low-threshold electron-counting measurements. Here, the cosmogenic activity of relevant long-lived radioisotopes induced in the experiment has been estimated to set requirements and procedures during preparation of the experiment and to check that it is not dominant over primordial radioactivity; particular attention has been paid to the activation of the 120 t of UAr used in DarkSide-20k. Expected exposures above ground and production rates, either measured or calculated, have been considered in detail. From the simulated counting rates in the detector due to cosmogenic isotopes, it is concluded that activation in copper and stainless steel is not problematic. The activity of ³⁹Ar induced during extraction, purification and transport on surface is evaluated to be 2.8% of the activity measured in UAr by DarkSide-50 experiment, which used the same underground source, and thus considered acceptable. Other isotopes in the UAr such as ³⁷Ar and ³H are shown not to be relevant due to short half-life and assumed purification methods.</p></div>","PeriodicalId":55439,"journal":{"name":"Astroparticle Physics","volume":"152 ","pages":"Article 102878"},"PeriodicalIF":3.5,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49709788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"MOONRAY: A permanent high-energy cosmic-ray observatory on the surface of the Moon","authors":"P.S. Marrocchesi","doi":"10.1016/j.astropartphys.2023.102879","DOIUrl":"10.1016/j.astropartphys.2023.102879","url":null,"abstract":"<div><p>The forthcoming decades will see a rapid development of space programs aiming at the implementation of habitats on our satellite. Therefore it makes sense to evaluate the feasibility of a permanent cosmic-ray (CR) observatory on the Moon. Its large sensitive area would allow to carry out a very rich observational program over a time span of a few decades with an unprecedented energy reach. A thorough exploration of the energy region around the CR spectral anomaly located at a few PeV, also known as the “knee”, will become possible.</p><p>In this paper we propose an innovative concept of a <em>modular</em> lunar observatory designed to overcome the limitations of the present generation of cosmic-ray telescopes in Low Earth Orbit. It consists of an array of fully independent modules with limited individual size and weight. This would allow an ample flexibility in the gradual deployment of a progressively larger active volume, while ensuring the collection of meaningful scientific data during the intermediate stages of its implementation. Each independent module consists of three main instruments: a combined Charge and Time-of-Flight detector to identify individual elements from proton to nickel (and beyond), a tracker providing the direction and impact point of the incident particle, and a calorimeter to measure its kinetic energy. The design of each instrument contains innovative solutions that are well within the reach of the present technology.</p></div>","PeriodicalId":55439,"journal":{"name":"Astroparticle Physics","volume":"152 ","pages":"Article 102879"},"PeriodicalIF":3.5,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45041951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of longitudinal development of air showers in the knee energy range","authors":"Feng Zhang ,&nbsp;Hu Liu ,&nbsp;Fengrong Zhu ,&nbsp;Jacob Oloketuyi","doi":"10.1016/j.astropartphys.2023.102877","DOIUrl":"10.1016/j.astropartphys.2023.102877","url":null,"abstract":"<div><p><span>Ground-based cosmic ray experiments detect cosmic ray mainly by measuring the longitudinal and lateral distribution of secondary particles produced in the extensive air shower<span> (EAS). The EAS of cosmic ray in the knee energy region is simulated via CORSIKA software. Several simulation samples with different energy, composition and zenith angles were carried out to understand the longitudinal development of electron, muon and Cherenkov light in EAS. All the results presented were obtained assuming an observation plane at an altitude of 4400 m a.s.l. The differences of longitudinal development between electron and Cherenkov light were studied, and the reconstruction uncertainty of shower maximum for electron from Cherenkov light was estimated to be 10–15 g/cm</span></span><span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span> for nuclei above 1 PeV. The performances of energy measurement and the composition discrimination ability based on longitudinal development were studied and compared with that from lateral distribution. It was found that number of electron per depth at its shower maximum has the smallest shower-to-shower fluctuations, but the shower-to-shower fluctuations of electron density measured at observation level was very close to it when the appropriate zenith angle was employed. The shower-to-shower fluctuations of shower maximum for electron is 50–55 g/cm<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span> for proton, and 20–25 g/cm<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span> for iron, but the composition discrimination ability between nuclei from muon density measured at observation level is much better than the shower maximum variable from longitudinal development. The hadronic model dependencies of the longitudinal development and lateral distribution were also discussed.</p></div>","PeriodicalId":55439,"journal":{"name":"Astroparticle Physics","volume":"152 ","pages":"Article 102877"},"PeriodicalIF":3.5,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47737687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluations of uncertainties in simulations of propagation of ultrahigh-energy cosmic-ray nuclei derived from microscopic nuclear models","authors":"E. Kido ,&nbsp;T. Inakura ,&nbsp;M. Kimura ,&nbsp;N. Kobayashi ,&nbsp;S. Nagataki ,&nbsp;N. Shimizu ,&nbsp;A. Tamii ,&nbsp;Y. Utsuno","doi":"10.1016/j.astropartphys.2023.102866","DOIUrl":"10.1016/j.astropartphys.2023.102866","url":null,"abstract":"<div><p>Photodisintegration is a main energy loss process for ultrahigh-energy cosmic-ray (UHECR) nuclei in intergalactic space. Therefore, it is crucial to understand systematic uncertainty in photodisintegration when simulating the propagation of UHECR nuclei. In this work, we calculated the cross sections using the random phase approximation (RPA) of density functional theory (DFT), a microscopic nuclear model. We calculated the <span><math><mrow><mi>E</mi><mn>1</mn></mrow></math></span> strength of 29 nuclei using three different density functionals. We obtained the cross sections of photonuclear reactions, including photodisintegration, with the <span><math><mrow><mi>E</mi><mn>1</mn></mrow></math></span> strength. Then, we implemented the cross sections in the cosmic-ray propagation code CRPropa. We found that assuming certain astrophysical parameter values, the difference between UHECR energy spectrum predictions using the RPA calculation and the default photodisintegration model in CRPropa can be more than the statistical uncertainty of the spectrum. We also found that the differences between the RPA calculations and CRPropa default in certain astrophysical parameters obtained by a combined fit of UHECR energy spectrum and composition data assuming a phenomenological model of UHECR sources can be more than the uncertainty of the data.</p></div>","PeriodicalId":55439,"journal":{"name":"Astroparticle Physics","volume":"152 ","pages":"Article 102866"},"PeriodicalIF":3.5,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43038931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Life cycle analysis of the GRAND experiment","authors":"Leidy T. Vargas-Ibáñez ,&nbsp;Kumiko Kotera ,&nbsp;Odile Blanchard ,&nbsp;Peggy Zwolinski ,&nbsp;Alexis Cheffer ,&nbsp;Mathieu Collilieux ,&nbsp;Paul Lambert ,&nbsp;Quentin Lefèbvre ,&nbsp;Thomas Protois","doi":"10.1016/j.astropartphys.2023.102903","DOIUrl":"https://doi.org/10.1016/j.astropartphys.2023.102903","url":null,"abstract":"<div><p><span>The goal of our study is to assess the environmental impact of the installation and use of the Giant Radio Array for Neutrino Detection (GRAND) prototype detection units, based on the life cycle assessment (LCA) methodology, and to propose recommendations that contribute to reduce the environmental impacts of the project at later stages. The functional unit, namely the quantified description of the studied system and of the performance requirements it fulfils, is to detect radio signals autonomously during 20 years, with 300 detection units deployed over 200</span> <!-->km<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span><span> in the Gansu province in China (corresponding to the prototype GRANDProto300). We consider four main phases: the extraction of the materials and the production of the detection units (upstream phases), the use and the end-of-life phases (downstream phases), with transportation between each step. An inventory analysis is performed for the seven components of each detection unit, based on transparent assumptions. Most of the inventory data are taken from the Idemat2021 database (Industrial Design &amp; Engineering Materials). Our results show that the components with the highest environmental impact are the antenna structure and the battery. The most pregnant indicators are ‘resource use’, mineral and metals’; ‘resource use, fossils’; ‘ionizing radiation, human health’; ‘climate change’; and ‘acidification’. Therefore, the actions that we recommend in the first place aim at reducing the impact of these components. They include limiting the mass of the raw material used in the antenna, changing the alloy of the antenna, considering another type of battery with an extended useful life, and the use of recycled materials for construction. As a pioneering study applying the LCA methodology to a large-scale physics experiment, this work can serve as a basis for future assessments by other collaborations.</span></p></div>","PeriodicalId":55439,"journal":{"name":"Astroparticle Physics","volume":"155 ","pages":"Article 102903"},"PeriodicalIF":3.5,"publicationDate":"2023-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49761350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A study on performance boost of a 17 m class Cherenkov telescope with a SiPM-based camera","authors":"Cornelia Arcaro ,&nbsp;Michele Doro ,&nbsp;Julian Sitarek ,&nbsp;Dominik Baack","doi":"10.1016/j.astropartphys.2023.102902","DOIUrl":"https://doi.org/10.1016/j.astropartphys.2023.102902","url":null,"abstract":"<div><p>The current generation of Imaging Atmospheric Cherenkov Telescopes (IACTs), comprised of major installations such as the MAGIC<span>, H.E.S.S. and VERITAS telescopes, is sometimes called the 3rd generation of such instruments. These telescopes use multipixel cameras composed of hundreds up to thousands photomultiplier tubes (PMTs). The supremacy of PMTs is currently being challenged by photon sensors, rapidly spreading in popularity: the silicon photomultipliers (SiPMs), that are becoming a valid alternative thanks to their high PDE, low operating voltage and flexibility in installation. In this report, we investigate the performance of an existing 3rd generation IACT array (taking as a working example MAGIC), in which PMTs would be replaced with SiPMs, applying generalized simulations, not tuned for a specific hardware solution. We find an energy-dependent improvement in sensitivity, reaching a factor of three at the current trigger threshold energy. Interestingly, we also find that the stronger sensitivity of SiPMs in the red part of the spectrum, a source of background for IACTs, does not affect this performance.</span></p></div>","PeriodicalId":55439,"journal":{"name":"Astroparticle Physics","volume":"155 ","pages":"Article 102902"},"PeriodicalIF":3.5,"publicationDate":"2023-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91987546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Avoiding parameter fine-tuning in mass varying neutrino models of DE?","authors":"Michael Maziashvili,&nbsp;Vakhtang Tsintsabadze","doi":"10.1016/j.astropartphys.2023.102901","DOIUrl":"https://doi.org/10.1016/j.astropartphys.2023.102901","url":null,"abstract":"<div><p>Coupled models of quintessence are usually introduced for avoiding or mitigating the parameter fine-tuning problem. At the same time, the coupled models should avoid the fine-tuning problem related to the initial conditions as quintessence models do. One more attractive feature of coupled models might be the explanation of the timescale at which the coincidence of DE and matter energy densities occur and the understanding of reason why after this the DE takes over. And finally, all these nice features should be unaffected by the quantum corrections of the potential. Having in mind these remarks, we shall focus our discussion on mass varying neutrino model of DE with inverse power-law potential to see how naturally does it work.</p></div>","PeriodicalId":55439,"journal":{"name":"Astroparticle Physics","volume":"154 ","pages":"Article 102901"},"PeriodicalIF":3.5,"publicationDate":"2023-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49710413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"GRMHD study of accreting massive black hole binaries in astrophysical environment: A review","authors":"Federico Cattorini ,&nbsp;Bruno Giacomazzo","doi":"10.1016/j.astropartphys.2023.102892","DOIUrl":"10.1016/j.astropartphys.2023.102892","url":null,"abstract":"<div><p>We present an overview of recent numerical advances in the theoretical characterization of massive binary black hole (MBBH) mergers in astrophysical environments. These systems are among the loudest sources of gravitational waves (GWs) in the universe and particularly promising candidates for multimessenger astronomy. Coincident detection of GWs and electromagnetic (EM) signals from merging MBBHs is at the frontier of contemporary astrophysics. One major challenge in observational efforts searching for these systems is the scarcity of strong predictions for EM signals arising before, during, and after merger. Therefore, a great effort in theoretical work to-date has been to characterize EM counterparts emerging from MBBHs concurrently to the GW signal, aiming to determine distinctive observational features that will guide and assist EM observations. To produce sharp EM predictions of MBBH mergers it is key to model the binary inspiral down to coalescence in a full general relativistic fashion by solving Einstein’s field equations coupled with the magnetohydrodynamics equations that govern the evolution of the accreting plasma in strong-gravity. We review the general relativistic numerical investigations that have explored the astrophysical manifestations of MBBH mergers in different environments and focused on predicting potentially observable smoking-gun EM signatures that accompany the gravitational signal.</p></div>","PeriodicalId":55439,"journal":{"name":"Astroparticle Physics","volume":"154 ","pages":"Article 102892"},"PeriodicalIF":3.5,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43682094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"EUSO-SPB1 mission and science","authors":"G. Abdellaoui ,&nbsp;S. Abe ,&nbsp;J.H. Adams Jr. ,&nbsp;D. Allard ,&nbsp;G. Alonso ,&nbsp;L. Anchordoqui ,&nbsp;A. Anzalone ,&nbsp;E. Arnone ,&nbsp;K. Asano ,&nbsp;R. Attallah ,&nbsp;H. Attoui ,&nbsp;M. Ave Pernas ,&nbsp;R. Bachmann ,&nbsp;S. Bacholle ,&nbsp;M. Bagheri ,&nbsp;M. Bakiri ,&nbsp;J. Baláz ,&nbsp;D. Barghini ,&nbsp;S. Bartocci ,&nbsp;M. Battisti ,&nbsp;A. Zuccaro Marchi","doi":"10.1016/j.astropartphys.2023.102891","DOIUrl":"10.1016/j.astropartphys.2023.102891","url":null,"abstract":"<div><p>The Extreme Universe Space Observatory on a Super Pressure Balloon 1 (EUSO-SPB1) was launched in 2017 April from Wanaka, New Zealand. The plan of this mission of opportunity on a NASA super pressure balloon test flight was to circle the southern hemisphere. The primary scientific goal was to make the first observations of ultra-high-energy cosmic-ray extensive air showers (EASs) by looking down on the atmosphere with an ultraviolet (UV) fluorescence telescope from suborbital altitude (33 km). After 12 days and 4 h aloft, the flight was terminated prematurely in the Pacific Ocean. Before the flight, the instrument was tested extensively in the West Desert of Utah, USA, with UV point sources and lasers. The test results indicated that the instrument had sensitivity to EASs of <span><math><mrow><mo>⪆</mo><mn>3</mn></mrow></math></span> EeV. Simulations of the telescope system, telescope on time, and realized flight trajectory predicted an observation of about 1 event assuming clear sky conditions. The effects of high clouds were estimated to reduce this value by approximately a factor of 2. A manual search and a machine-learning-based search did not find any EAS signals in these data. Here we review the EUSO-SPB1 instrument and flight and the EAS search.</p></div>","PeriodicalId":55439,"journal":{"name":"Astroparticle Physics","volume":"154 ","pages":"Article 102891"},"PeriodicalIF":3.5,"publicationDate":"2023-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47229884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}