In view of High Luminosity LHC upgrade, the ATLAS experiment will add a new layer of Resistive Plate Chambers (RPC) trigger chambers into the barrel muon spectrometer. These next -generation RPC chambers will use a 1 mm gap and a single type of readout strips coupled to front-end electronics capable of providing both coordinates in the detector plane. The procedures for assembling the readout panels and the results of Quality Assurance and Quality Control (QA/QC) tests on the pre -series panels is reported here.
The Extreme Energy Events (EEE) Project, a joint project of the Centro Fermi (Museo Storico della Fisica e Centro Studi e Ricerche "E. Fermi") and INFN, has a dual purpose: a scientific research program on cosmic rays at ground level and an intense outreach and educational program. The project consists in a network of about 60 tracking detectors, called telescopes, mostly hosted in Italian High Schools. Each telescope is made by three Multigap Resistive Plate Chambers, operated so far with a gas mixture composed by 98% C2H2F4 and 2% SF6. Due to its high Global Warming Potential, a few years ago the EEE collaboration has started an extensive R&D on alternative mixtures environmentally sustainable and compatible with the current experimental setup and operational environment. Among other gas mixtures, the one with helium and hydrofluoroolefin R1234ze gave the best result during the preliminary tests performed with two of the network telescopes. The detector has proved to reach performance levels comparable to those obtained with previous mixtures, without any modification of the hardware. We will discuss the first results obtained with the new mixture, tested with different percentages of the two components.
To take full advantage from the LHC upgrade to high luminosity in 2029, the ATLAS community has approved an intensive detector upgrade program that includes the construction of an additional trigger layer positioned close to the BI MDT chambers of the muon spectrometer. These chambers are RPC with thin gas gap, thin High Pressure Laminate electrodes coated with graphite on one side, and only use strips orthogonal to the beam-axis to reconstruct the eta and phi coordinates of the detector point where an ionizing particle passes. A detailed description of the construction and validation of these strip panels in China and Italy assembly sites, is presented here.
The Extreme Energy Events (EEE) Collaboration is fully involved in an ecological transition. The use of the standard gas mixture, C2H2F4 + SF6, has stopped in favor of an alternative green mixture based on C3H2F4 with the addition of He or CO2. The choise of these new mixtures is motivated by the significant lower Global Warming Potential (GWP) to reduce the emission of gases potentially contributing to the greenhouse effect. The EEE experiment consists of 61 muon telescopes based on Multigap Resistive Plate Chambers (MRPCs), each telescope composed of 3 chambers filled with gas. Several EEE detectors are today completely fluxed with the new ecological mixture. This contribution will report recent results about the telescope performance obtained from studies with the eco-friendly alternative mixture carried out in the last years.
The Extreme Energy Events (EEE) Project was born to include scientific, outreach and educational purposes. It is designed to detect and study high energy cosmic rays through the detection of the extensive air shower's muon component through an array of muon telescopes based on Multigap Resistive Plate Chambers (MRPC) GPS synchronized. The telescopes are organized in local clusters and single telescope stations distributed all over the Italian territory and installed mainly in high schools buildings. These unconventional working sites offer young learners the opportunity to get in touch with the world of high energy physics research. Every year hundreds of students and teachers are involved in the activities. The EEE Collaboration regularly schedules on-line activities: monthly meetings, masterclasses and seminars. Activities focusing on the upgrade phase of the EEE Project have been carried out in the last two years, with enormous success and participation. This contribution will present a general overview of the EEE outreach activities and the future plan.
The INFN Outreach Cosmic Ray Activities (OCRA) project counts 24 of the institute's divisions all over Italy as members and offers activities both for students and teachers. The International Cosmic Day - ICD, organized by DESY, is one of OCRA activity common to all local groups and consist in inviting high school students to carry out hands-on measurements of the cosmic ray flux and learn about the related physics background. This paper will describe in detail the latest edition of the OCRA ICD, which was organized both in-person at the different venues and online, with a focus on the educational value of the two modes, also through the use of a questionnaire administered to participating students after the end of the day's activities.
The need for reducing the emission of gases, potentially contributing to the greenhouse effect and climate change, has impacted many fields, including scientific research. The Extreme Energy Event (EEE) collaboration started, already several years ago, a series of tests aiming at finding a more eco-friendly replacement for the gases used in the Multigap Resistive Plate Chambers (MRPCs) of its network. These tests identified a promising binary gas mixture, and data taking has begun with a subset of the telescopes of the EEE network, making EEE the first experiment in the world completely implemented with MRPCs and operating with an eco-friendly gas mixture. Here the results of the tests and a preliminary comparison of the telescope performance measured with the standard (non eco-friendly) and the new eco-friendly gas mixtures are presented and discussed.
AbstractAfter its successful campaign of measurements beyond the Polar Arctic Circle, the PolarquEEEst experiment measured the cosmic charged particle rate at sea level in a latitude interval between 35$$^{\circ }$$ ∘ N and 82$$^{\circ }$$ ∘ N. In this paper, these measurements are described and the corresponding results are discussed.
. - The MoCRiL (Measurements of Cosmic Rays in Lake) project has re-prop osed, in an educational way and using modern measuring instruments, Domenico Pacini's experiment for determining the origin of the natural ionizing radiation that surrounds us in any instant. The students of 4 different schools from the Calabria Region with the collaboration of the INFN researchers (OCRA Collaboration of Cosenza) and of the Physics department of UNICAL, performed the measurement of the ionizing particle rate at different depths in the waters of the Arvo Lake in the Sila plateau (1300 m asl). The aim of this project is to let students know and understand the often very difficult way that leads to scientific discovery, sharing ideas and results with other students, from different years and schools, and with teachers and researchers.
A bstract The ratio $$ \mathcal{R} $$ R = Γ( K S → πeν ) / Γ( K S → π + π − ) has been measured with a sample of 300 million K S mesons produced in ϕ → K L K S decays recorded by the KLOE experiment at the DAΦNE e + e − collider. K S → πeν events are selected by a boosted decision tree built with kinematic variables and time-of-flight measurements. Data control samples of K L → πeν decays are used to evaluate signal selection efficiencies. With 49647 ± 316 signal events we measure $$ \mathcal{R} $$ R = (1 . 0421 ± 0 . 0066 stat ± 0 . 0075 syst ) × 10 − 3 . The combination with our previous measurement gives $$ \mathcal{R} $$ R = (1 . 0338 ± 0 . 0054 stat ± 0 . 0064 syst ) × 10 − 3 . From this value we derive the branching fraction $$ \mathcal{B} $$ B ( K S → πeν ) = (7 . 153 ± 0 . 037 stat ± 0 . 044 syst ) × 10 − 4 and f + (0) |V us | = 0 . 2170 ± 0 . 009.
The MoCRiL (Measurements of Cosmic Rays in Lake) project has re-proposed, in an educational way and using modern measuring instruments, Domenico Pacini’s experiment for determining the origin of the natural ionizing radiation that surrounds us in any instant. The students of 4 different schools from Calabria Region with the collaboration of the INFN researchers (OCRA collaboration of Cosenza [1]) and of the Physics department of UNICAL, performed the measurement of the ionizing particle rate at different depths in the waters of the Arvo Lake in the Sila plateau (1300 m asl). The aim of this project is to let students know and understand the often very difficult way that leads to scientific discovery, sharing ideas and results with other students, from different years and schools, and with teachers and researchers.
The Extreme Energy Events (EEE) experiment, a joint project of the Centro Fermi and INFN Italian national research institutes, has a dual purpose: a scientific research program for measurements of the cosmic rays flux at ground level and an intense outreach and educational program with an active contribution of students and teachers in the construction and operation of the detectors in High Schools. The network counts 60 tracking detectors, each made by three Multigap Resistive Plate Chambers (MRPC), operated so far with a gas mixture composed by 98% C2H2F4 and 2% SF6. Given its high Global Warming Potential (GWP), the collaboration, since few years, started a R&D on alternative mixtures environmentally sustainable. Latest results on a C3H2F4 + He eco-friendly mixture are here presented.
The Extreme Energy Events (EEE) 'telescope' is made by 3 Multigap Resistive Plate Chambers (MRPC), each with an active area of 158x82 cm(2) in size. Each detector is part of a large network of about sixty telescopes spread over the Italian territory. Due to the good tracking capabilities (100 ps time resolution and cm(2) spatial resolution) the EEE telescope can be used also as test station for large area detectors. The link between the EEE track and signals from the detector under test can be obtained by implementing a streaming DAQ with a common time reference between the two systems given by the GPS signal. The installation and first results of the cosmic muon test facility with the EEE MRPC telescope based on the low-cost, streaming-compatible 12 channels, 250MHz, 14 bits digitizer (INFN-WaveBoard or WB) developed by the JLAB12 Collaboration, is presented.
The Outreach Cosmic Ray Activities (OCRA) project was created in 2018 within the Italian Istituto Nazionale di Fisica Nucleare (INFN) to offer a platform for all outreach activities focusing on cosmic rays within the institute. OCRA now counts 22 of the institute's divisions all over Italy as members. The project offers activities both for students and teachers. The one activity common to all local groups is the participation in the yearly International Cosmic Day, organized by DESY, inviting high school students to carry out hands-on measurements of the cosmic ray flux and learn about the related physics background. Two students from each division are then selected to participate in the annual OCRA science camp, a three-day full immersion into the life of a physicist. For both teachers and students, the OCRA website https://web.infn.it/OCRA/, offers a series of online laboratories designed both to be used by students individually but also to be offered in the classroom by teachers. A section dedicated to teachers provides ample material to help bring these laboratories to the classroom. The online materials were presented in a course for teachers in spring 2021. In addition to the national efforts, there are also local initiatives of the OCRA member groups: workshops and secondments, science competitions and the development of new detectors for outreach activities offer a multitude of possibilities for students to engage with our researchers and to explore the world of cosmic rays. This article provides an overview on all activities offered by OCRA with a particular focus on the 2022 science camp.
Tests of the T, CP and CPT symmetries in the neutral kaon system are performed by the direct comparison of the probabilities of a kaon transition process to its symmetry-conjugate. The exchange of in and out states required for a genuine test involving an antiunitary transformation implied by time-reversal is implemented exploiting the entanglement of K0K‾0 pairs produced at a ϕ-factory.A data sample collected by the KLOE experiment at DAΦNE corresponding to an integrated luminosity of about 1.7 fb−1 is analysed to study the Δt distributions of the ϕ→KSKL→π+π−π±e∓ν and ϕ→KSKL→π±e∓ν3π0 processes, with Δt the difference of the kaon decay times. A comparison of the measured Δt distributions in the asymptotic region Δt≫τS allows to test for the first time T and CPT symmetries in kaon transitions with a precision of few percent, and to observe CP violation with this novel method.
The Extreme Energy Events Project (EEE) represents a breakthrough in outreach activities in Cosmic Ray Physics: high school students are protagonists of an experiment to measure Extensive Air Showers at ground. They start their experience at CERN with the construction of the three high performing Multigap Resistive Plate Chambers constituting the telescope that is then installed inside their school; then they take care of the telescope operation and data analysis. Presently 60 telescopes are installed in Italy and, since 2014, coordinated data taking have been performed during each school year providing a huge amount of candidate muon tracks. Every year hundreds of students and teachers are involved in the activities directly correlated to EEE. The COVID-19 pandemic has strongly affected the experimental activities of the EEE Project. However in the last two years the online activities were strengthened, with an intense programme of collaboration meetings, masterclasses, and hugely successful topical seminars. Starting from the fall of 2021, the improvement of epidemiological situation made it possible to start some of the EEE activities in presence.
Elevated levels of glutathione S-transferases (GSTs) play a major role as a mechanism of resistance to insecticides and acaricides in resistant pest insects and mites, respectively. Such compounds are either detoxicated directly via phase I metabolism or detoxicated by phase II metabolism of metabolites as formed by microsomal monooxygenases. Here we used monochlorobimane (MCB) as an artificial substrate and glutathione to determine total GST activity in equivalents of single pest insects and spider mites in a sensitive 96-well plate-based assay system by measuring the enzymatic conversion of MCB to its fluorescent bimane-glutathione adduct. The differentiation by their GST activity between several strains of the two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae), with different degrees of resistance to numerous acaricides was more sensitive with MCB compared to the commonly used substrate 1-chloro-2,4-dinitrobenzene (CDNB). Compared to an acaricide-susceptible reference strain, one field population of T. urticae showed a more than 10-fold higher GST activity measured with MCB, in contrast to a less than 2-fold higher activity when CDNB was used. Furthermore, we showed that GST activity can be sensitively assessed with MCB in homogenates of pest insects such as Heliothis virescens, Spodoptera frugiperda (Lepidoptera: Noctuidae), Plutella xylostella (Lepidoptera: Yponomeutidae), and Myzus persicae (Hemiptera: Aphididae).
Large-size Resistive Micromegas have been chosen for the upgrade of the forward muon spectrometer of the ATLAS experiment, the New Small Wheel project. These chambers, together with small-strip Thin Gap Chambers (sTGC), allow reconstruction of high-momentum muon tracks in a high-radiation environment and provide a robust low-threshold single-muon trigger. A collaboration of seven INFN units built 32 SM1 type chambers, corresponding to one fourth of the total number needed for this upgrade. Each SM1 chamber has a surface of approximately 2 m2 and four sensitive layers. The production was shared among five INFN construction sites and it was completed in fall 2020. The construction methods, as well as the results of the quality tests done on components of the detector and on the assembled chambers, are reported in the present paper.
The Outreach Cosmic Ray Activities (OCRA) project offers a platform for all outreach activities focusing on cosmic rays within the Italian Istituto Nazionale di Fisica Nucleare (INFN). Created in 2018, OCRA now counts 21 of the institute's divisions all over Italy as members. The project's core activity is the participation of all its members in the International Cosmic Day, organized by DESY, and inviting high school students to carry out hands-on measurements of the cosmic ray flux and learn about the related physics background. Two students from each division are then selected to participate in the annual OCRA science camp, a three-day full immersion into the life of a physicist. The national activities are complemented by local initiatives of the OCRA member groups: workshops and tutorship programs, science competitions and the development of new detectors for outreach activities offer a multitude of possibilities for students to engage with our researchers and to explore the world of cosmic rays. Since spring of 2020 OCRA also offers a series of online laboratories on its website https://web.infn.it/OCRA/, designed not only to be used by students individually but also to be used in the classroom by teachers. Here we will give an overview on all activities offered by OCRA with a particular focus on the 2020 online event organized in occasion of the International Cosmic Day, that saw the participation of more than 3000 students.
This Letter reports the observation of WWW production and a measurement of its cross section using 139 fb^{-1} of proton-proton collision data recorded at a center-of-mass energy of 13 TeV by the ATLAS detector at the Large Hadron Collider. Events with two same-sign leptons (electrons or muons) and at least two jets, as well as events with three charged leptons, are selected. A multivariate technique is then used to discriminate between signal and background events. Events from WWW production are observed with a significance of 8.0 standard deviations, where the expectation is 5.4 standard deviations. The inclusive WWW production cross section is measured to be 820±100 (stat)±80 (syst) fb, approximately 2.6 standard deviations from the predicted cross section of 511±18 fb calculated at next-to-leading-order QCD and leading-order electroweak accuracy.