A
bstract
We consider quantum-decoherence effects in neutrino oscillation data. Working in the open quantum system framework we adopt a phenomenological approach that allows to parameterize the ...energy dependence of the decoherence effects. We consider several phenomenological models. We analyze data from the reactor experiments RENO, Daya Bay and KamLAND and from the accelerator experiments NOvA, MINOS/MINOS+ and T2K. We obtain updated constraints on the decoherence parameters quantifying the strength of damping effects, which can be as low as Γ
ij
≲ 8 × 10
−
27
GeV at 90% confidence level in some cases. We also present sensitivities for the future facilities DUNE and JUNO.
One of the most common expectations of a quantum theory of gravity is that space-time is uncertain or fluctuating at microscopic scales, making it a stochastic medium for particle propagation. ...Particles traversing this space-time may experience fluctuations in travel times or velocities, together referred to as lightcone fluctuations, with even very small effects potentially accumulating into observable signals over large distances. In this work we present a heuristic model of lightcone fluctuations and study the resulting modifications to neutrino propagation, including neutrino decoherence and arrival time spread. We show the expected scale of such effects due to `natural' Planck scale physics and consider how they may be observed in neutrino detectors, and compare the potential of neutrinos to \(\gamma\)-ray astronomy. Using simulations of neutrino mass states propagating in a fluctuating environment, we determine an analytic decoherence operator in the framework of open quantum systems to quantitatively evaluate neutrino decoherence resulting from lightcone fluctuations, allowing experimental constraints on neutrino decoherence to be connected to Planck scale fluctuations in space-time and \(\gamma\)-ray results.
Neutrinos undergoing stochastic perturbations as they propagate experience decoherence, damping neutrino oscillations over distance. Such perturbations may result from fluctuations in space-time ...itself if gravity is a quantum force, including interactions between neutrinos and virtual black holes. In this work we model the influence of heuristic neutrino-virtual black hole interaction scenarios on neutrino propagation and evaluate the resulting signals in astrophysical and atmospheric neutrinos. We demonstrate how these effects can be represented in the framework of open quantum systems, allowing experimental constraints on such systems to be connected to quantum gravitational effects. Finally, we consider the energy-dependence of such Planck scale physics at energies observed in current neutrino experiments, and show that sensitivity to Planck scale physics well below the `natural' expectation is achievable in certain scenarios.
The anomalous magnetic moments of leptons can be both measured and theoretically predicted with high precision, and as such provide stringent tests of the Standard Model (SM) of particle physics. The ...anomalous magnetic moment of the muon, in particular offers sensitivity to new physics within the reach of current experiments. The current world’s best measurement of muon anomalous magnetic moment made at the Brookhaven National Laboratory (BNL) deviates from the SM prediction by over 3σ, providing a tantalising but inconclusive hint that contributions from new physics may be present. A new muon anomalous magnetic moment experiment is currently under construction at the Fermi National Accelerator Laboratory (Fermilab), known as the Fermilab muon g-2 experiment. Due to commence in 2017, this new experiment is expected to improve the experimental measurement precision of the muon anomalous magnetic moment by a factor of 4, and is seeking to confirm or reject the current discrepancy. The experiment, like its BNL predecessor, will measure the precession of the muon spin in a magnetic storage-ring. This new experiment has three straw tracking detectors used to measure the beam profile of the stored muons, as well as other dynamic properties of the beam. This thesis describes the design of these detectors, and the data acquisition system and subsequent data processing systems that have been developed to read them out and make their data available for physics analysis. The performance of the straw trackers and the readout systems at a number of beam tests and test stands is presented, in addition to Monte-Carlo simulations of the trackers in the final experiment.
We consider quantum-decoherence effects in neutrino oscillation data. Working in the open quantum system framework we adopt a phenomenological approach that allows to parameterize the energy ...dependence of the decoherence effects. We consider several phenomenological models. We analyze data from the reactor experiments RENO, Daya Bay and KamLAND and from the accelerator experiments NOvA, MINOS/MINOS+ and T2K. We obtain updated constraints on the decoherence parameters quantifying the strength of damping effects, which can be as low as \(\Gamma_{ij} \lesssim 8 \times 10^{-27}\) GeV at 90% confidence level in some cases. We also present sensitivities for the future facilities DUNE and JUNO.
The anomalous magnetic moments of leptons can be both measured and theoretically predicted with high precision, and as such provide stringent tests of the Standard Model (SM) of particle physics. The ...anomalous magnetic moment of the muon, in particular offers sensitivity to new physics within the reach of current experiments. The current world’s best measurement of muon anomalous magnetic moment made at the Brookhaven National Laboratory (BNL) deviates from the SM prediction by over 3σ, providing a tantalising but inconclusive hint that contributions from new physics may be present. A new muon anomalous magnetic moment experiment is currently under construction at the Fermi National Accelerator Laboratory (Fermilab), known as the Fermilab muon g-2 experiment. Due to commence in 2017, this new experiment is expected to improve the experimental measurement precision of the muon anomalous magnetic moment by a factor of 4, and is seeking to confirm or reject the current discrepancy. The experiment, like its BNL predecessor, will measure the precession of the muon spin in a magnetic storage-ring. This new experiment has three straw tracking detectors used to measure the beam profile of the stored muons, as well as other dynamic properties of the beam. This thesis describes the design of these detectors, and the data acquisition system and subsequent data processing systems that have been developed to read them out and make their data available for physics analysis. The performance of the straw trackers and the readout systems at a number of beam tests and test stands is presented, in addition to Monte-Carlo simulations of the trackers in the final experiment.
To provide global estimates of diabetes prevalence for 2019 and projections for 2030 and 2045.
A total of 255 high-quality data sources, published between 1990 and 2018 and representing 138 countries ...were identified. For countries without high quality in-country data, estimates were extrapolated from similar countries matched by economy, ethnicity, geography and language. Logistic regression was used to generate smoothed age-specific diabetes prevalence estimates (including previously undiagnosed diabetes) in adults aged 20–79 years.
The global diabetes prevalence in 2019 is estimated to be 9.3% (463 million people), rising to 10.2% (578 million) by 2030 and 10.9% (700 million) by 2045. The prevalence is higher in urban (10.8%) than rural (7.2%) areas, and in high-income (10.4%) than low-income countries (4.0%). One in two (50.1%) people living with diabetes do not know that they have diabetes. The global prevalence of impaired glucose tolerance is estimated to be 7.5% (374 million) in 2019 and projected to reach 8.0% (454 million) by 2030 and 8.6% (548 million) by 2045.
Just under half a billion people are living with diabetes worldwide and the number is projected to increase by 25% in 2030 and 51% in 2045.
Background
Resource constraints may inhibit the provision of appropriate interventions for children with neurodisabilities presenting with behavioural sleep problems. Telephone calls (TC), as opposed ...to home visits (HV), may be a more resource efficient means of supporting these families.
Objective
To conduct a preliminary investigation exploring the feasibility and acceptability of replacing HV with TC to support parents implementing sleep management strategies and to gather evidence to inform the design and methods of a full trial.
Methods
Parents referred to a sleep management intervention routinely delivered by a community paediatric team were alternately allocated to receive implementation support via HV (n = 7) or TC (n = 8). Activity logs recorded the frequency, duration and mode of support. Parents and practitioners were interviewed about their experiences of receiving/delivering the intervention.
Results
Intervention drop‐out was low, the frequency, number of contacts and intervention duration appeared comparable. Parents allocated TC received less contact time. Parents valued implementation support irrespective of delivery mode and practitioners reported that despite initial reservations, implementation support via TC appeared to work well.
Conclusions
TC appears an acceptable and convenient mode of delivering sleep support, valued by both parents and practitioners. We recommend a full‐scale trial to investigate effectiveness.
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