A Unique Oscillation Solution to the Solar Neutrino Problem?

A global two-neutrino oscillation fit combining Super-Kamiokande solar neutrino data with the solar neutrino rates measured by Homestake, Gallex/GNO, SAGE and SNO prefers a single allowed area, the Large Mixing Angle solution, at about 95% confidence level. The mass^2 difference between the two mass eigenstates is Delta m^2 approx 3-25 x 10^-5 eV^2, the mixing angle theta is tan^2 theta approx 0.21-0.67.Comment: 10 pages, 3 figures, to be published in the proceedings of the NOON 2001 worksho

A case study of the barriers and enablers affecting teaching staff e-learning provision

Presented at the International Conference on Information Communication Technologies in Education, 7-9 July, 2016, Rhodes Greece.The present paper reports the outputs of a focus group examining the perceived uses, enablers and barriers of utilising virtual learning environments (VLEs), amongst a small group of postgraduate teachers. Sixteen pedagogical/teaching functions were identified and were mapped to MacLean and Scott’s (2011) model of VLE elements. Whilst a number of enablers of VLE use were apparent, participants’ insights and inputs indicated a larger number of VLE barriers. It appears that the biggest barrier to overcome in using VLEs is finding the time to develop the materials and navigate the technology

Attitudes towards, and utilisation of, virtual learning environments among postgraduate university teaching staff

Skill retention within a virtual learning environment (VLE) is dependent upon the complexity inherent in skill use (Cahillane, MacLean, & Smy, 2015) and the frequency of skill use (Arthur, Bennett, Stanush, & McNally, 1998). A questionnaire was used to capture demographics and perceptions/attitudes concerning VLE usefulness, VLE ease of use and self-reported VLE use among postgraduate level teachers. Results indicate that self-reported teaching workloads were negatively associated with attitudinal positivity. Further results indicated that the attitudinal concept of Perceived usefulness explained a significant amount of unique variance in VLE Use. However, perceptions concerning the Ease of VLE use did not

Neutrinos from failed supernovae at future water and liquid argon detectors

We discuss the diffuse flux of electron neutrinos and antineutrinos from cosmological failed supernovae, stars that collapse directly into a black hole, with no explosion. This flux has a hotter energy spectrum compared to regular, neutron-star forming collapses, and therefore it dominates the total diffuse flux from core collapses above 20-45 MeV of neutrino energy. Reflecting the features of the originally emitted neutrinos, the flux of nu_e and anti-nu_e at Earth is larger for larger survival probability of these species, and for stiffer equations of state of nuclear matter. In the energy window 19-29 MeV, the flux from failed supernovae is susbtantial, ranging from 7% to a dominant fraction of the total flux from all core collapses. It can be as large as phi = 0.38 s^{-1} cm^{-2} for anti-nu_e (phi = 0.28 s^{-1} cm^{-2} for nue), normalized to a local rate of core collapses of R_{cc}(0)=10^{-4} yr^{-1} Mpc^{-3}. In 5 years, a 0.45 Mt water Cherenkov detector should see 5-65 events from failed supernovae, while up to 160 events are expected for the same mass with Gadolinium addition. A 0.1 Mt liquid argon experiment should record 1-11 events. Signatures of neutrinos from failed supernovae are the enhancement of the total rates of events from core collapses (up to a factor of 2) and the appearance of high energy tails in the event spectra.Comment: LaTeX, 30 pages, 10 figures, 4 tables. Some clarifications added, new section of discussion added, references updated. Version to appear in Phys. Rev.

Simulating fast time variations in the supernova neutrino flux in Hyper-Kamiokande

Hyper-Kamiokande is a proposed next-generation water Cherenkov detector. If a galactic supernova happens, it will deliver a high event rate ($\mathcal{O}(10^5)$ neutrino events in total) as well as event-by-event energy information. Recent supernova simulations exhibit the Standing Accretion Shock Instability (SASI) which causes oscillations in the number flux and mean energy of neutrinos. The amplitude of these oscillations is energy-dependent, so the energy information available in Hyper-Kamiokande could be used to improve the detection prospects of these SASI oscillations. To determine whether this can be achieved in the presence of detector effects like backgrounds and finite energy uncertainty, we have started work on a detailed simulation of Hyper-Kamiokande's response to a supernova neutrino burst

Expression of Interest: The Atmospheric Neutrino Neutron Interaction Experiment (ANNIE)

Neutron tagging in Gadolinium-doped water may play a significant role in reducing backgrounds from atmospheric neutrinos in next generation proton-decay searches using megaton-scale Water Cherenkov detectors. Similar techniques might also be useful in the detection of supernova neutrinos. Accurate determination of neutron tagging efficiencies will require a detailed understanding of the number of neutrons produced by neutrino interactions in water as a function of momentum transferred. We propose the Atmospheric Neutrino Neutron Interaction Experiment (ANNIE), designed to measure the neutron yield of atmospheric neutrino interactions in gadolinium-doped water. An innovative aspect of the ANNIE design is the use of precision timing to localize interaction vertices in the small fiducial volume of the detector. We propose to achieve this by using early production of LAPPDs (Large Area Picosecond Photodetectors). This experiment will be a first application of these devices demonstrating their feasibility for Water Cherenkov neutrino detectors.Comment: Submitted for the January 2014 Fermilab Physics Advisory Committee meetin

Expression of Interest: The Atmospheric Neutrino Neutron Interaction Experiment (ANNIE)

Submitted for the January 2014 Fermilab Physics Advisory Committee meetingSubmitted for the January 2014 Fermilab Physics Advisory Committee meetingSubmitted for the January 2014 Fermilab Physics Advisory Committee meetingSubmitted for the January 2014 Fermilab Physics Advisory Committee meetingNeutron tagging in Gadolinium-doped water may play a significant role in reducing backgrounds from atmospheric neutrinos in next generation proton-decay searches using megaton-scale Water Cherenkov detectors. Similar techniques might also be useful in the detection of supernova neutrinos. Accurate determination of neutron tagging efficiencies will require a detailed understanding of the number of neutrons produced by neutrino interactions in water as a function of momentum transferred. We propose the Atmospheric Neutrino Neutron Interaction Experiment (ANNIE), designed to measure the neutron yield of atmospheric neutrino interactions in gadolinium-doped water. An innovative aspect of the ANNIE design is the use of precision timing to localize interaction vertices in the small fiducial volume of the detector. We propose to achieve this by using early production of LAPPDs (Large Area Picosecond Photodetectors). This experiment will be a first application of these devices demonstrating their feasibility for Water Cherenkov neutrino detectors