Ultra-long-lived particles searches with MATHUSLA Marsella, G.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2019, Volume:
936
Journal Article
Peer reviewed
Open access
There are many theoretical motivations for long-lived particle (LLP) signals at the LHC in a comprehensive survey of Standard Model (SM) extensions. LLPs are a common prediction of a wide range of ...theories that address unsolved fundamental mysteries such as naturalness, dark matter, baryogenesis and neutrino masses, and represent a natural and generic possibility for physics beyond the SM (BSM). MATHUSLA (MAssive Timing Hodoscope for Ultra Stable neutraL pArticles) is a proposal for a minimally instrumented, large-volume surface detector to detect such LLPs. The MATHUSLA surface detector will consist of an air-filled decay volume surrounded by charged particles detectors (top, bottom, and sides) that provide timing and a robust multilayer tracking system located in the upper region. The collaboration proposes covering a total sensitive area of (200 × 200) square meters on the surface in the region near the interaction point of ATLAS or CMS detectors for the beginning of the HL-LHC run.
The DArk Matter Particle Explorer (DAMPE), one of the four scientific space science missions within the framework of the Strategic Pioneer Program on Space Science of the Chinese Academy of Sciences, ...is a general purpose high energy cosmic-ray and gamma-ray observatory, which was successfully launched on December 17th, 2015 from the Jiuquan Satellite Launch Center. The DAMPE scientific objectives include the study of galactic cosmic rays up to ∼ 10 TeV and hundreds of TeV for electrons/gammas and nuclei respectively, and the search for dark matter signatures in their spectra. In this paper we illustrate the layout of the DAMPE instrument, and discuss the results of beam tests and calibrations performed on ground. Finally we present the expected performance in space and give an overview of the mission key scientific goals.
We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we ...obtain a radiation energy of 15.8±0.7(stat)±6.7(syst) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principles calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.
Pathogens deploy effector proteins that interact with host proteins to manipulate the host physiology to the pathogen's own benefit. However, effectors can also be recognized by host immune proteins, ...leading to the activation of defence responses. Effectors are thus essential components in determining the outcome of plant–pathogen interactions. Despite major efforts to decipher effector functions, our current knowledge on effector biology is scattered and often limited. In this study, we conducted two systematic large‐scale yeast two‐hybrid screenings to detect interactions between Arabidopsis thaliana proteins and effectors from two vascular bacterial pathogens: Ralstonia pseudosolanacearum and Xanthomonas campestris. We then constructed an interactomic network focused on Arabidopsis and effector proteins from a wide variety of bacterial, oomycete, fungal, and invertebrate pathogens. This network contains our experimental data and protein–protein interactions from 2,035 peer‐reviewed publications (48,200 Arabidopsis–Arabidopsis and 1,300 Arabidopsis–effector protein interactions). Our results show that effectors from different species interact with both common and specific Arabidopsis interactors, suggesting dual roles as modulators of generic and adaptive host processes. Network analyses revealed that effector interactors, particularly “effector hubs” and bacterial core effector interactors, occupy important positions for network organization, as shown by their larger number of protein interactions and centrality. These interactomic data were incorporated in EffectorK, a new graph‐oriented knowledge database that allows users to navigate the network, search for homology, or find possible paths between host and/or effector proteins. EffectorK is available at www.effectork.org and allows users to submit their own interactomic data.
EffectorK (www.effectorK.org) is an open database compiling newly generated and literature‐curated interactomic data from various Arabidopsis pathogen effectors.
The DArk Matter Particle Explorer (DAMPE), a satellite-based cosmic ray and gamma-ray detector, was launched on December 17, 2015, and began its on-orbit operation on December 24, 2015. In this work ...we document the on-orbit calibration procedures used by DAMPE and report the calibration results of the Plastic Scintillator strip Detector (PSD), the Silicon-Tungsten tracKer-converter (STK), the BGO imaging calorimeter (BGO), and the Neutron Detector (NUD). The results are obtained using Galactic cosmic rays, bright known GeV gamma-ray sources, and charge injection into the front-end electronics of each sub-detector. The determination of the boundary of the South Atlantic Anomaly (SAA), the measurement of the live time, and the alignments of the detectors are also introduced. The calibration results demonstrate the stability of the detectors in almost two years of the on-orbit operation.
Abstract
The Cherenkov Telescope Array (CTA) is a next-generation ground-based observatory for gamma-ray astronomy at very high energies. The Large-Sized Telescope prototype (LST-1) is located at the ...CTA-North site, on the Canary Island of La Palma. LSTs are designed to provide optimal performance in the lowest part of the energy range covered by CTA, down to ≃20 GeV. LST-1 started performing astronomical observations in 2019 November, during its commissioning phase, and it has been taking data ever since. We present the first LST-1 observations of the Crab Nebula, the standard candle of very-high-energy gamma-ray astronomy, and use them, together with simulations, to assess the performance of the telescope. LST-1 has reached the expected performance during its commissioning period—only a minor adjustment of the preexisting simulations was needed to match the telescope’s behavior. The energy threshold at trigger level is around 20 GeV, rising to ≃30 GeV after data analysis. Performance parameters depend strongly on energy, and on the strength of the gamma-ray selection cuts in the analysis: angular resolution ranges from 0.°12–0.°40, and energy resolution from 15%–50%. Flux sensitivity is around 1.1% of the Crab Nebula flux above 250 GeV for a 50 hr observation (12% for 30 minutes). The spectral energy distribution (in the 0.03–30 TeV range) and the light curve obtained for the Crab Nebula agree with previous measurements, considering statistical and systematic uncertainties. A clear periodic signal is also detected from the pulsar at the center of the Nebula.
Layout and performance of RPCs used in the Argo-YBJ experiment Aielli, G.; Assiro, R.; Bacci, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2006, Volume:
562, Issue:
1
Journal Article
Peer reviewed
The layout of the RPCs, used in the Argo-YBJ experiment to image with a high space-time granularity the atmospheric shower, is described in this paper. The detector has been assembled to provide both ...digital and analog informations in order to cover a wide particle density range with a time accuracy of 1
ns. The experimental results obtained operating the chambers in streamer mode at sea level with a standard gas mixture are presented.
Plastic scintillators are widely used for anti-coincidence systems and for the identification of charged cosmic-ray nuclei in satellite experiments. For this reason, a plastic scintillator detector ...(PSD) should have a high detection efficiency for charged cosmic rays and a very good capability of measuring charges. We implemented a full and customizable simulation tool to investigate the performance of a PSD coupled to Silicon Photomultipliers. The overall performance of the detector is studied by tracking optical photons produced inside the scintillator. The simulation will be used for the design of a PSD for future space experiments, such as HERD, AMEGO, e-Astrogam. In this work we investigated in detail the effect of Birks’ saturation in the discrimination of charged ions up to iron nuclei. We will show the comparison between simulations and measurements conducted on prototype scintillator tiles.
Satellite experiments for gamma-ray and cosmic-ray detection employ plastic scintillators to discriminate charged from neutral particles in order to correctly identify gamma-rays and charged nuclei. ...The High Energy Cosmic Radiation Detection (HERD) facility will be among these experiments, to be installed onboard the future Chinese Space Station (CSS), to detect cosmic-rays and gamma-rays up to TeV energies. The plastic scintillator detector (PSD) will consist of scintillator tiles or bars coupled to Silicon Photomultipliers (SiPMs). To discriminate gamma-rays from charged particles and measure the ion charge up to iron nuclei a wide dynamic range is required, from few tens up to thousands of photoelectrons. We have equipped a plastic scintillator tile prototype with SiPMs produced by Hamamatsu and AdvanSiD and coupled their analog signals to the DT5550W board based on the CITIROC ASIC, produced by CAEN SpA. The CITIROC ASIC allows both the formation of a fast trigger with a configurable threshold and the digitization of analog waveforms after a preamplification and shaping stage along two paths with different gain settings. The performance of our prototype will be shown.
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