Understanding pretence and understanding action

Two studies were carried out in an attempt to replicate an earlier but controversial set of findings that suggested that young children are able to understand pretence in a mentalistic sense (Hickling, Wellman, & Gottfried, 1997). In Study 1, 65 three-year-olds and 77 four-year-olds were asked to either judge the thoughts of an absent teddy bear, who had not witnessed a change in the original pretence stipulation, or were asked to complete a similar, standard false-belief task. Study 2 repeated the experimental procedures of the first study with 24 three-year-olds and 16 four-year-olds, with the difference that all children had to complete both tasks in a single session. The results obtained across both studies showed that 3-year-olds were unable to correctly judge the discrepant thoughts of the teddy bear, suggesting that young children do not attribute a false belief to another actor during pretend play, and that instead they view pretence in terms of overt action

Interpersonal influences on young children's understanding of mind

The thesis represents a critical examination of the theory-theory account of young children's understanding of mind, as explored through six empirical studies carried out on 661 children. Beginning with a critique of both experimental and naturalistic approaches to the study of mind, the thesis proceeds to establish a set of guiding research principles drawn from the philosophy of mind. Following a philosophical critique of the major psychological accounts of children's understanding of mind, it is suggested that the theory-theory comes closest to satisfying the proposed philosophical guidelines. The empirical studies reported suggest that children as young as three have a clear understanding of representations, as well as a developing theory of mind. It is proposed that certain patterns of interpersonal relatedness facilitate young children's understanding of both mental and nonmental representations. In particular, it was found that an experimenter's reference to a deceptive interaction facilitated young children's understanding of false belief. The fluent knowledge of a second language was similarly found to facilitate young children's ability to remember their own previous false belief, as well as their ability to understand the appearance-reality distinction. Although the present research is founded on the use of the false belief paradigm, a critical discussion of its limitations suggests that developmentalists need to explore the interpersonal cooperation surrounding young children's developing theories of mind. It is also argued that the false belief paradigm can no longer be the dominant research paradigm if progress is to continue to be made in this field. It is suggested that future research has much to gain by adopting the principle that an understanding of mind is primarily an understanding of interpersonal relations

Final results for the neutron β-asymmetry parameter A₀ from the UCNA experiment

The UCNA experiment was designed to measure the neutron β-asymmetry parameter A0 using polarized ultracold neutrons (UCN). UCN produced via downscattering in solid deuterium were polarized via transport through a 7 T magnetic field, and then directed to a 1 T solenoidal electron spectrometer, where the decay electrons were detected in electron detector packages located on the two ends of the spectrometer. A value for A0 was then extracted from the asymmetry in the numbers of counts in the two detector packages. We summarize all of the results from the UCNA experiment, obtained during run periods in 2007, 2008–2009, 2010, and 2011–2013, which ultimately culminated in a 0.67% precision result for A₀

Light Sterile Neutrinos: A White Paper

This white paper addresses the hypothesis of light sterile neutrinos based on recent anomalies observed in neutrino experiments and the latest astrophysical data

Search for electron antineutrino appearance in a long-baseline muon antineutrino beam

Electron antineutrino appearance is measured by the T2K experiment in an accelerator-produced antineutrino beam, using additional neutrino beam operation to constrain parameters of the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing matrix. T2K observes 15 candidate electron antineutrino events with a background expectation of 9.3 events. Including information from the kinematic distribution of observed events, the hypothesis of no electron antineutrino appearance is disfavored with a significance of 2.40σ and no discrepancy between data and PMNS predictions is found. A complementary analysis that introduces an additional free parameter which allows non-PMNS values of electron neutrino and antineutrino appearance also finds no discrepancy between data and PMNS predictions

Sensitivity of super-kamiokande with gadolinium to low energy antineutrinos from pre-supernova emission

Supernova detection is a major objective of the Super-Kamiokande (SK) experiment. In the next stage of SK (SK-Gd), gadolinium (Gd) sulfate will be added to the detector, which will improve the ability of the detector to identify neutrons. A core-collapse supernova (CCSN) will be preceded by an increasing flux of neutrinos and antineutrinos, from thermal and weak nuclear processes in the star, over a timescale of hours; some of which may be detected at SK-Gd. This could provide an early warning of an imminent CCSN, hours earlier than the detection of the neutrinos from core collapse. Electron antineutrino detection will rely on inverse beta decay events below the usual analysis energy threshold of SK, so Gd loading is vital to reduce backgrounds while maximizing detection efficiency. Assuming normal neutrino mass ordering, more than 200 events could be detected in the final 12 hr before core collapse for a 15–25 solar mass star at around 200 pc, which is representative of the nearest red supergiant to Earth, α-Ori (Betelgeuse). At a statistical false alarm rate of 1 per century, detection could be up to 10 hr before core collapse, and a pre-supernova star could be detected by SK-Gd up to 600 pc away. A pre-supernova alert could be provided to the astrophysics community following gadolinium loading

Searching for supernova bursts in Super-Kamiokande IV

Super-Kamiokande has been searching for neutrino bursts characteristic of core-collapse supernovae continuously, in real time, since the start of operations in 1996. The present work focuses on detecting more distant supernovae whose event rate may be too small to trigger in real time, but may be identified using an offline approach. The analysis of data collected from 2008 to 2018 found no evidence of distant supernovae bursts. This establishes an upper limit of 0.29 yr−1 on the rate of core-collapse supernovae out to 100 kpc at 90% C.L. For supernovae that fail to explode and collapse directly to black holes the limit reaches to 300 kpc