293 research outputs found
JUNO Detector Design and Status
No full textThe Jiangmen Underground Neutrino Observatory (JUNO) is a next generation multipurpose liquid scintillator detector being built in China. It will address a wide range of topics in neutrino physics: the determination of the neutrino mass ordering and the sub-percent measurement of three oscillation parameters from reactor neutrino oscillations, detection of solar, atmospheric and supernova neutrinos as well as the search for physics beyond the Standard Model. The JUNO detector design is optimised towards the determination of the neutrino mass ordering by reaching an unprecedented energy resolution and a low background. The experimental hall, which was recently successfully dug out, is located under about 700~m of granite overburden. The center of the instrument consists of a 35.4-meter diameter acrylic vessel containing 20 kt of LAB-based liquid scintillator, making it the largest liquid scintillator detector in the world. The spherical detector is submerged in a water pool shielding doubling as a water Cherenkov detector which, along with a top tracker above it, serves to precisely reconstruct and veto atmospheric muons. Surrounding the vessel are 17612 20” photomultiplier tubes (PMTs) and 25600 3” PMTs, which will collect the light induced by neutrinos interacting in the detector. This document presents the detector design and construction status of JUNO, which is expected to start taking data in 2023on behalf of the JUNO collaborationinfo:eu-repo/semantics/publishe
Multi-messenger triggered searches with the ANTARES Neutrino Telescope
No full textInternational audienceThe ANTARES neutrino telescope has been operating for thirteen years in the Mediterranean sea with the purpose of searching for high-energy cosmic neutrinos. During the last years, multi-messenger astronomy has become one of the most exciting topics for Cherenkov neutrino detectors, and probably the best strategy to identify the neutrino sources. Thus, the ANTARES Collaboration is actively participating to the follow-up of alerts sent by different experiments, covering the full electromagnetic spectrum and gravitational wave interferometers. ANTARES' real-time response to these alerts is complemented with dedicated offline analyses, the latter being the focus of this talk. These studies allowed to set upper limits that constrain the neutrino emission from various sources, including Fast Radio Bursts, Gamma Ray Bursts and compact binary mergers, as well as neutrino alerts by others neutrino observatories (IceCube, GVD). The latest results are presented here
The KM3NeT multi-PMT optical module
No full textThe optical module of the KM3NeT neutrino telescope is an innovative multi-faceted large area photodetection module. It contains 31 three-inch photomultiplier tubes in a single 0.44 m diameter pressure-resistant glass sphere. The module is a sensory device also comprising calibration instruments and electronics for power, readout and data acquisition. It is capped with a breakout-box with electronics for connection to an electro-optical cable for power and long-distance communication to the onshore control station. The design of the module was qualified for the first time in the deep sea in 2013. Since then, the technology has been further improved to meet requirements of scalability, cost-effectiveness and high reliability. The module features a sub-nanosecond timing accuracy and a dynamic range allowing the measurement of a single photon up to a cascade of thousands of photons, suited for the measurement of the Cherenkov radiation induced in water by secondary particles from interactions of neutrinos with energies in the range of GeV to PeV. A distributed production model has been implemented for the delivery of more than 6000 modules in the coming few years with an average production rate of more than 100 modules per month. In this paper a review is presented of the design of the multi-PMT KM3NeT optical module with a proven effective background suppression and signal recognition and sensitivity to the incoming direction of photons.0info:eu-repo/semantics/publishe
Data-driven core collapse supernova multilateration with first neutrino events
No full textA Galactic core-collapse supernova (CCSN) is likely to be observed in neutrino detectors around the world minutes to hours before the electromagnetic radiation arrives. The SNEWS2.0 network of neutrino and dark matter detectors aims to use the relative arrival times of the neutrinos at the different experiments to point back to the supernova so as to facilitate follow-up observation. One of the simplest methods to estimate the CCSN direction is to use the first neutrino events detected through the inverse beta decay (IBD) process, v̄ep → e+n. We will consider neutrino detectors sensitive to IBD interactions with low backgrounds. The difference in signal arrival times between a large and a small detector will be biased, however, with the first event at the smaller detector, on average, arriving later than that at the larger detector. This bias can be mitigated by using these first events in a data-driven approach without recourse to simulations or models. The resulting method requires, at minimum, only the times of the first events at most detectors, along with a longer time series of events from one larger detector to act as a reference lightcurve. In this article, we demonstrate this method and its uncertainty estimate using pairs of detectors of different sizes and with different supernova distances. Finally, we use this method to calculate probability skymaps using four detectors currently in operation (Super-Kamiokande, JUNO, LVD, and SNO+) and show that the calculated probabilities yield appropriate confidence intervals for all supernova directions. The area of the 68\% confidence interval varies by distance and direction, but is expected to be a few thousand square degrees. The resulting skymaps should be useful for the multi-messenger community as a rapid, initial pointing to follow up on the SNEWS2.0 Galactic CCSN neutrino alert
Translation of AhizadeAbdulhalim Effendi's Work Named Shawahid al- Nubuwwe(Review-Text)
No full textŞevahidü‟n-nübüvve, Molla Cami‟nin h. 885 (m. 1480) yılında Farsça kaleme aldığı dini bir eserdir. Molla Cami‟nin sade bir Farsça ile yazdığı bu eser; Hz. Muhammed‟in peygamberlik delillerini anlatan yaklaşık 500 rivayetten meydana gelir. Şevahidü‟n-nübüvve‟nin Türkçeye dört tercümesi yapılmıştır. Bu tercümelerden sonuncusu Ahizade Abdülhalim Efendi tarafından yapılmıştır. Ahizade Abdülhalim Efendi, XVI. yüzyılın ikinci yarısında yaşamış; İstanbul, Bursa ve Edirne'de farklı vazifelerde bulunmuş önemli bir devlet adamıdır. Ahizade, kadılık, kazaskerlik, müderrislik gibi görevlerinin yanında; mütercimlik, hattatlık ve şairlik gibi meziyetlere sahip çok yönlü bir şahsiyettir.O aynı zamanda, tefsir, hadis, fıkıh, tasavvuf ve edebiyat gibi alanlarda eserler vermiş velud bir Alimdir. Onun eserlerinden biri de h. 1009 ( m. 1600/1601) yılında Molla Cami‟nin Şevahidü‟n-nübüvve adlı eserinin tercümesidir. Bu çalışmada, eserin müellifi olan Molla Cami ve mütercimi Ahizade Abdülhalim Efendi‟nin hayatı, eserleri hakkında bilgiler verilmiştir. Ayrıca Şevahidü‟n-nübüvve‟nin Farsçası göz önünde bulundurularak, Türkçeye çevrilen diğer tercümelerle kısa bir mukayesesi yapılmıştır. Ahizade‟nin yapmış olduğu tercümenin 25 yazma nüshası tespit edilerek tanıtılmıştır. Müellif nüshası elde bulunmayan yazmanın, ilmi usullere göre seçilen en uygun üç nüshası çalıĢmaya esas alınarak tenkitli metin hazırlanmıştır. Ayrıca Ahizade‟nin Şevahidü‟n-nübüvve Tercümesi‟nin geniş bir incelemesi yapılmış ve süslü nesir yer yer orta nesir örneği olan bu yazmanın daha iyi anlaşılması için metinden hareketle bir sözlük hazırlanmıştır.Shawahid al-Nubuwwe is a religious work written by Molla Jami h. 885 (1480) in Persian. This work, written by Molla Jami in plain Persian consists of approximately 500 narratives telling the proofs of Muhammad's prophethood. Four translations of Shawahid al-Nubuwwe were made into Turkish. The last of these translations was made by Ahizade Abdulhalim Effendi. AhizadeAbdulhalim Effendi is an important statesman who lived in the second half of XVI. century and held different duties in Istanbul, Bursa and Edirne. In addition to his duties such as judge, judge of the army, professor; Ahizade is a sophisticated personality with talents such as translator, calligrapher and poetry. He is also a prolific scholar who has produced works in fields such as exegesis, hadith, fiqh, sufism and literature. Shewahid al-Nubuwwe, too, isone of his works, which he translated from Molla Jami in h. 1009 (1600/1601). In this study, informations are given about the life and works of Molla Jami, the author of the work, and its translator Ahizade Abdulhalim Effendi. In addition, a short comparison was made with the other translations that translated into Turkish, taking the Persian copy of the book into consideration. 25 manuscript copies of the translation made by Ahizade were identified and introduced. The criticized text was prepared on the basis of the three most appropriate copies of the manuscript, which the copy written by the author is not available, selected according to scientific methods. In addition, a comprehensive examination of Ahizade's Translation of Shawahid al-Nubuwwe was made
Traditional values of virginity and sexual behaviour in rural Ethiopian youth: results from a cross-sectional study
No full textAbstract Background Delaying sexual initiation has been promoted as one of the methods of decreasing risks of HIV among young people. In traditional countries, such as Ethiopia, retaining virginity until marriage is the norm. However, no one has examined the impact of this traditional norm on sexual behaviour and risk of HIV in marriage. This study examined the effect of virginity norm on having sex before marriage and sexual behaviour after marriage among rural Ethiopian youth. Methods We did a cross-sectional survey in 9 rural and 1 urban area using a probabilistic sample of 3,743 youth, 15–24 years of age. Univariate analysis was used to assess associations between virginity norm and gender stratified by area, and between sexual behaviour and marital status. We applied Kaplan-Meier and Cox regression analysis to estimate age at sexual debut and assessed the predictors of premarital sex among the never-married using SPSS. Results We found that maintaining virginity is still a way of securing marriage for girls, especially in rural areas; the odds of belief and intention to marry a virgin among boys was 3–4 times higher among rural young males. As age increased, the likelihood of remaining a virgin decreased. There was no significant difference between married and unmarried young people in terms of number of partners and visiting commercial sex workers. Married men were twice more likely to have multiple sexual partners than their female counterparts. A Cox regression show that those who did not believe in traditional values of preserving virginity (adjusted hazard ratio [AHR] = 2.91 [1.92–4.40]), alcohol drinkers (AHR = 2.91 [1.97–4.29]), Khat chewers (AHR = 2.36 [1.45–3.85]), literates (AHR = 18.01 [4.34–74.42]), and the older age group (AHR = 1.85 [1.19–2.91]) were more likely to have premarital sex than their counterparts. Conclusion Although virginity norms help delay age at sexual debut among rural Ethiopian youth, and thus reduces vulnerability to sexually transmitted infections and HIV infection, vulnerability among females may increase after marriage due to unprotected multiple risky sexual behaviours by spouses. The use of preventive services, such as VCT before marriage and condom use in marriage should be part of the HIV/AIDS prevention and control strategies.</p
Offline performance studies and first real-time results on Core-Collapse Supernova neutrino searches with the KM3NeT neutrino detectors
No full textInternational audience→ Major breakthroughs in particle physics, astrophysics and nuclear physics from future observation of CCSN neutrinos! → Only 1-4 CCSN per century in our Galaxy, we do not want to miss the next one! The response of the KM3NeT detectors to CCSN neutrinos has been evaluated by means of a complete Monte Carlo simulation and an exhaustive study of the background from data. The detector performances are presented here. References [1] I. Tamborra et al., Phys. Rev. Lett. 111,121104 (2013) [2] KM3NeT Collaboration, Journal of Physics G 43 (8) (2016) [3] M. Ageron et al., arXiv:1906.02704 (2019) [physics.ins-det] [4] J.Miganda, arXiv:1609.04286 (2015) Core-collapse supernovae (CCSN) • Explosive phenomena can occur at the end of the life of massive stars. The explosion mechanism is not fully understood, but neutrinos play a fundamental role in it. • 99% of gravitational energy released through neu-trinos when photons cannot escape the star yet! • Single observation as of today: Only 24 neutrinos detected from SN1987A. Full simulation of the CCSN signal • State-of-the-art 3D simulations of three CCSN progenitors (with 27 M , 20 M and 11 M) provided by the Garching group are used for this study [1]. They only account for the accretion phase, with limited duration. • Time dependent CCSN neutrino spectrum: quasi-thermal distribution depending on the average neutrino energyẼ ν , the neutrino luminosity L(t) ν SN , the spectral pinching shape parameter α, and the SN distance. • The simulation output is used to compute the CCSN neutrino interaction rate in sea water. • Full Monte Carlo simulation of the detector response has been developed to estimate the expected detection rates. The KM3NeT neutrino detectors and the supernova neutrino signa
Combining neutrino experimental light-curves for pointing to the next galactic core-collapse supernova
No full textInternational audienceThe multi-messenger observation of the next galactic core-collapse supernova will shed light on the different physical processes involved in these energetic explosions. Good timing and pointing capabilities of neutrino detectors would help in the search for an electromagnetic or gravitational-wave counterparts. An approach for the determination of the arrival time delay of the neutrino signal at different experiments using a direct detected neutrino light-curve matching is discussed. A simplified supernova model and detector simulation are used for its application. The arrival time delay and its uncertainty between two neutrino detectors are estimated with chi-square and cross-correlation methods. The direct comparison of the detected light-curves offers the advantage to be model-independent. Millisecond time resolution on the arrival time delay at two different detectors is needed. Using the computed time delay between different combinations of currently operational and future detectors, a triangulation method is used to infer the supernova localisation in the sky. The combination of IceCube, Hyper-Kamiokande, JUNO and KM3NeT/ARCA provides a 90% confidence area of . These low-latency analysis methods can be implemented in the SNEWS alert system
Prospects for Heavy Neutral Lepton Searches at Short and Medium Baseline Reactor Experiments
No full textHeavy neutrinos with masses in the MeV range can in principle simultaneously explain the light neutrino masses and the origin of baryonic matter in the universe. The strongest constraints on their properties come from their potential impact on the formation of light elements in the early universe. Since these constraints rely on assumptions about the cosmic history, independent checks in the laboratory are highly desirable. In this paper, we discuss the opportunity to search for heavy neutrinos within the MeV mass range in short and medium baseline reactor neutrino experiments, using the SoLid, JUNO and TAO experiments as examples. These experiments can give the currently strongest upper bound on the mixing between the light electron neutrinos and the heavy neutrino in the 2-9 MeV mass range
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