91 research outputs found

    Boosted dark matter at neutrino experiments

    Get PDF
    Current and future neutrino experiments can be used to discover dark matter, not only in searches for dark matter annihilating to neutrinos, but also in scenarios where dark matter itself scatters off standard model particles in the detector. In this work, we study the sensitivity of different neutrino detectors to a class of models called boosted dark matter, in which a subdominant component of a dark sector acquires a large Lorentz boost today through annihilation of a dominant component in a dark matter-dense region, such as the galactic Center or dwarf spheroidal galaxies. This analysis focuses on the sensitivity of different neutrino detectors, specifically the Cherenkov-based Super-K and the future argon-based DUNE to boosted dark matter that scatters off electrons. We study the dependence of the expected limits on the experimental features, such as energy threshold, volume and exposure in the limit of constant scattering amplitude. We highlight experiment-specific features that enable current and future neutrino experiments to be a powerful tool in finding signatures of boosted dark matter

    Michel electron reconstruction using cosmic-ray data from the MicroBooNE LArTPC

    Get PDF
    The MicroBooNE liquid argon time projection chamber (LArTPC) has been taking data at Fermilab since 2015 collecting, in addition to neutrino beam, cosmic-ray muons. Results are presented on the reconstruction of Michel electrons produced by the decay at rest of cosmic-ray muons. Michel electrons are abundantly produced in the TPC, and given their well known energy spectrum can be used to study MicroBooNE's detector response to low-energy electrons (electrons with energies up to ∌ 50 MeV). We describe the fully-automated algorithm developed to reconstruct Michel electrons, with which a sample of ∌ 14,000 Michel electron candidates is obtained. Most of this article is dedicated to studying the impact of radiative photons produced by Michel electrons on the accuracy and resolution of their energy measurement. In this energy range, ionization and bremsstrahlung photon production contribute similarly to electron energy loss in argon, leading to a complex electron topology in the TPC. By profiling the performance of the reconstruction algorithm on simulation we show that the ability to identify and include energy deposited by radiative photons leads to a significant improvement in the energy measurement of low-energy electrons. The fractional energy resolution we measure improves from over 30% to ∌ 20% when we attempt to include radiative photons in the reconstruction. These studies are relevant to a large number of analyses which aim to study neutrinos by measuring electrons produced by Îœ e interactions over a broad energy range. Keywords: Michel electrons, LArTPC, MicroBooN

    Ionization electron signal processing in single phase LArTPCs. Part I. Algorithm Description and quantitative evaluation with MicroBooNE simulation

    Get PDF
    We describe the concept and procedure of drifted-charge extraction developed in the MicroBooNE experiment, a single-phase liquid argon time projection chamber (LArTPC). This technique converts the raw digitized TPC waveform to the number of ionization electrons passing through a wire plane at a given time. A robust recovery of the number of ionization electrons from both induction and collection anode wire planes will augment the 3D reconstruction, and is particularly important for tomographic reconstruction algorithms. A number of building blocks of the overall procedure are described. The performance of the signal processing is quantitatively evaluated by comparing extracted charge with the true charge through a detailed TPC detector simulation taking into account position-dependent induced current inside a single wire region and across multiple wires. Some areas for further improvement of the performance of the charge extraction procedure are also discussed. Keywords: MicroBooNE, Signal Processing, Deconvolution, ROIUnited States. Department of Energy. High Energy Physics DivisionNational Science Foundation (U.S.)Swiss National Science FoundationScience and Technology Facilities Council (Great Britain)Royal Society (Great Britain

    Gifted children with ADHD: how are they different from non-gifted children with ADHD?

    Get PDF
    The present study focused on inattention and hyperactivity/impulsivity differences of gifted children with and without attention deficit-hyperactivity disorder (ADHD). Based on clinical assessment utilizing the Anxiety Disorders Interview Schedule for Children (ADISC-IV) and the Wechsler Intelligence Scale for Children—Fourth Edition, attendees of a public outpatient child service (boys = 359, girls = 148), with mean age 10.60 years (SD = 3.08 years), were allocated into four groups: ADHD (N = 350), gifted (N = 15), gifted/ADHD (N = 18), and clinical controls (N = 124). The Strengths and Weaknesses of ADHD-Symptoms and Normal Behavior Scale dimensionally assessed inattention and hyperactivity/impulsivity variations. Compared to the gifted/ADHD group, the ADHD group had higher scores for inattention and comparable scores for hyperactivity/impulsivity. For most symptoms, the ADHD groups (gifted or not) rated higher than the non-ADHD groups (control and gifted without ADHD). Findings appeared to indicate that (i) ADHD is a valid diagnosis among children who are gifted, (ii) gifted children might tend to be less inattentive than non-gifted ADHD children, and (iii) ADHD-gifted children appear to differ from the non-ADHD-gifted children with regard to specific hyperactive and impulsive behaviors. The practical implication of these findings is that clinicians may wish to focus on these symptoms when diagnosing ADHD among children with high intelligence

    Noise Characterization and Filtering in the MicroBooNE Liquid Argon TPC

    Get PDF
    The low-noise operation of readout electronics in a liquid argon time projection chamber (LArTPC) is critical to properly extract the distribution of ionization charge deposited on the wire planes of the TPC, especially for the induction planes. This paper describes the characteristics and mitigation of the observed noise in the MicroBooNE detector. The MicroBooNE's single-phase LArTPC comprises two induction planes and one collection sense wire plane with a total of 8256 wires. Current induced on each TPC wire is amplified and shaped by custom low-power, low-noise ASICs immersed in the liquid argon. The digitization of the signal waveform occurs outside the cryostat. Using data from the first year of MicroBooNE operations, several excess noise sources in the TPC were identified and mitigated. The residual equivalent noise charge (ENC) after noise filtering varies with wire length and is found to be below 400 electrons for the longest wires (4.7 m). The response is consistent with the cold electronics design expectations and is found to be stable with time and uniform over the functioning channels. This noise level is significantly lower than previous experiments utilizing warm front-end electronics. Keywords: Cold Electronics; Noise; MicroBooNE; Time projection chambers; Noble liquid detectors; Neutrino detector

    Enfermidades determinadas pelo princípio radiomimético de Pteridium aquilinum (Polypodiaceae)

    Full text link

    Key steps for effective breast cancer prevention

    Get PDF

    A prenylated dsRNA sensor protects against severe COVID-19

    Get PDF
    Inherited genetic factors can influence the severity of COVID-19, but the molecular explanation underpinning a genetic association is often unclear. Intracellular antiviral defenses can inhibit the replication of viruses and reduce disease severity. To better understand the antiviral defenses relevant to COVID-19, we used interferon-stimulated gene (ISG) expression screening to reveal that OAS1, through RNase L, potently inhibits SARS-CoV-2. We show that a common splice-acceptor SNP (Rs10774671) governs whether people express prenylated OAS1 isoforms that are membrane-associated and sense specific regions of SARS-CoV-2 RNAs, or only express cytosolic, nonprenylated OAS1 that does not efficiently detect SARS-CoV-2. Importantly, in hospitalized patients, expression of prenylated OAS1 was associated with protection from severe COVID-19, suggesting this antiviral defense is a major component of a protective antiviral response

    A prenylated dsRNA sensor protects against severe COVID-19

    Get PDF
    Inherited genetic factors can influence the severity of COVID-19, but the molecular explanation underpinning a genetic association is often unclear. Intracellular antiviral defenses can inhibit the replication of viruses and reduce disease severity. To better understand the antiviral defenses relevant to COVID-19, we used interferon-stimulated gene (ISG) expression screening to reveal that OAS1, through RNase L, potently inhibits SARS-CoV-2. We show that a common splice-acceptor SNP (Rs10774671) governs whether people express prenylated OAS1 isoforms that are membrane-associated and sense specific regions of SARS-CoV-2 RNAs, or only express cytosolic, nonprenylated OAS1 that does not efficiently detect SARS-CoV-2. Importantly, in hospitalized patients, expression of prenylated OAS1 was associated with protection from severe COVID-19, suggesting this antiviral defense is a major component of a protective antiviral response
    • 

    corecore