| 1. |
- Özdemir, Metin, 1977-, et al.
(author)
-
Does promoting parents' negative attitudes to underage drinking reduce adolescents' drinking? : the mediating process and moderators of the effects of the Örebro prevention programme
- 2016
-
In: Addiction. - : Wiley-Blackwell. - 0965-2140 .- 1360-0443. ; 111:2, s. 263-271
-
Journal article (peer-reviewed)abstract
- Background and aims: The Örebro Prevention Programme (ÖPP) was found previously to be effective in reducing drunkenness among adolescents [Cohen's d = 0.35, number needed to treat (NNT) = 7.7]. The current study tested the mediating role of parents’ restrictive attitudes to underage drinking in explaining the effectiveness of the ÖPP, and the potential moderating role of gender, immigration status, peers’ and parents’ drinking and parent–adolescent relationship quality.Design: A quasi‐experimental matched‐control group study with assessments at baseline, and at 18‐ and 30‐month follow‐ups.Participants: Of the 895 target youths at ages 12–13 years, 811 youths and 651 parents at baseline, 653 youths and 524 parents at 18‐month and 705 youths and 506 parents at 30‐month follow‐up participated in the study.Measurements: Youths reported on their past month drunkenness, their parents’ and peers’ alcohol use and the quality of their relationship with parents. Parents reported on their attitudes to underage drinking.Findings: The mediation analyses, using latent growth curve modeling, showed that changes in parents’ restrictive attitudes to underage drinking explained the impact of the ÖPP on changes in youth drunkenness, which was reduced, and onset of monthly drunkenness, which was delayed, relative to controls. Mediation effect explained 57 and 45% of the effects on drunkenness and onset of monthly drunkenness, respectively. The programme effects on both parents’ attitudes and youth drunkenness were similar across gender, immigrant status, parents’ and peers’ alcohol use and parent–youth relationship quality.Conclusions: Increasing parents’ restrictive attitudes to youth drinking appears to be an effective and robust strategy for reducing heavy underage drinking regardless of the adolescents’ gender, cultural origin, peers’ and parents’ drinking and relationship quality with parents.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Mishchenko, Petr A., et al.
(author)
-
Chiral spin liquids with crystalline Z(2) gauge order in a three-dimensional Kitaev model
- 2020
-
In: Physical Review B. - : AMER PHYSICAL SOC. - 2469-9950 .- 2469-9969. ; 101:4
-
Journal article (peer-reviewed)abstract
- Chiral spin liquids (CSLs) are time-reversal-symmetry-breaking ground states of frustrated quantum magnets that show no long-range magnetic ordering but instead exhibit topological order and fractional excitations. Their realization in simple and tractable microscopic models has, however, remained an open challenge for almost two decades until it was realized that Kitaev models on lattices with odd-length loops are natural hosts for such states, even in the absence of a time-reversal-symmetry-breaking magnetic field. Here we report on the formation of CSLs in a three-dimensional Kitaev model on a hypernonagon lattice composed of nine-site loops, which differ from their widely studied two-dimensional counterparts; namely, they exhibit a crystalline ordering of the Z(2) gauge fluxes and thereby break some of the underlying lattice symmetries. We study the formation of these unconventional CSLs via extensive quantum Monte Carlo simulations and demonstrate that they are separated from the featureless paramagnet at high temperatures by a single first-order phase transition at which both time-reversal and lattice symmetries are simultaneously broken. Using variational approaches for the ground state, we explore the effect of varying the Kitaev couplings and find at least five distinct CSL phases, all of which possess crystalline ordering of the Z(2) gauge fluxes. For some of these phases, the complementary itinerant Majorana fermions exhibit gapless band structures with topological features such as Weyl nodes or nodal lines in the bulk and Fermi arc or drumhead surface states.
|
|
| 5. |
- Abbasi, R., et al.
(author)
-
Measurement of atmospheric neutrino mixing with improved IceCube DeepCore calibration and data processing
- 2023
-
In: Physical Review D. - 2470-0010 .- 2470-0029. ; 108:1
-
Journal article (peer-reviewed)abstract
- We describe a new data sample of IceCube DeepCore and report on the latest measurement of atmospheric neutrino oscillations obtained with data recorded between 2011-2019. The sample includes significant improvements in data calibration, detector simulation, and data processing, and the analysis benefits from a sophisticated treatment of systematic uncertainties, with significantly greater level of detail since our last study. By measuring the relative fluxes of neutrino flavors as a function of their reconstructed energies and arrival directions we constrain the atmospheric neutrino mixing parameters to be sin2θ23=0.51±0.05 and Δm322=2.41±0.07×10-3 eV2, assuming a normal mass ordering. The errors include both statistical and systematic uncertainties. The resulting 40% reduction in the error of both parameters with respect to our previous result makes this the most precise measurement of oscillation parameters using atmospheric neutrinos. Our results are also compatible and complementary to those obtained using neutrino beams from accelerators, which are obtained at lower neutrino energies and are subject to different sources of uncertainties.
|
|
| 6. |
- Abbasi, R., et al.
(author)
-
Citizen science for IceCube: Name that Neutrino
- 2024
-
In: European Physical Journal Plus. - 2190-5444. ; 139:6
-
Journal article (peer-reviewed)abstract
- Name that Neutrino is a citizen science project where volunteers aid in classification of events for the IceCube Neutrino Observatory, an immense particle detector at the geographic South Pole. From March 2023 to September 2023, volunteers did classifications of videos produced from simulated data of both neutrino signal and background interactions. Name that Neutrino obtained more than 128,000 classifications by over 1800 registered volunteers that were compared to results obtained by a deep neural network machine-learning algorithm. Possible improvements for both Name that Neutrino and the deep neural network are discussed.
|
|
| 7. |
- Abbasi, R., et al.
(author)
-
Search for Continuous and Transient Neutrino Emission Associated with IceCube's Highest-energy Tracks: An 11 yr Analysis
- 2024
-
In: Astrophysical Journal. - 1538-4357 .- 0004-637X. ; 964:1
-
Journal article (peer-reviewed)abstract
- IceCube alert events are neutrinos with a moderate-to-high probability of having astrophysical origin. In this study, we analyze 11 yr of IceCube data and investigate 122 alert events and a selection of high-energy tracks detected between 2009 and the end of 2021. This high-energy event selection (alert events + high-energy tracks) has an average probability of >= 0.5 of being of astrophysical origin. We search for additional continuous and transient neutrino emission within the high-energy events' error regions. We find no evidence for significant continuous neutrino emission from any of the alert event directions. The only locally significant neutrino emission is the transient emission associated with the blazar TXS 0506+056, with a local significance of 3 sigma, which confirms previous IceCube studies. When correcting for 122 test positions, the global p-value is 0.156 and compatible with the background hypothesis. We constrain the total continuous flux emitted from all 122 test positions at 100 TeV to be below 1.2 x 10-15 (TeV cm2 s)-1 at 90% confidence assuming an E -2 spectrum. This corresponds to 4.5% of IceCube's astrophysical diffuse flux. Overall, we find no indication that alert events in general are linked to lower-energetic continuous or transient neutrino emission.
|
|
| 8. |
- Abbasi, R., et al.
(author)
-
Search for decoherence from quantum gravity with atmospheric neutrinos
- 2024
-
In: Nature Physics. - 1745-2481 .- 1745-2473. ; 20:6, s. 913-920
-
Journal article (peer-reviewed)abstract
- Neutrino oscillations at the highest energies and longest baselines can be used to study the structure of spacetime and test the fundamental principles of quantum mechanics. If the metric of spacetime has a quantum mechanical description, its fluctuations at the Planck scale are expected to introduce non-unitary effects that are inconsistent with the standard unitary time evolution of quantum mechanics. Neutrinos interacting with such fluctuations would lose their quantum coherence, deviating from the expected oscillatory flavour composition at long distances and high energies. Here we use atmospheric neutrinos detected by the IceCube South Pole Neutrino Observatory in the energy range of 0.5-10.0 TeV to search for coherence loss in neutrino propagation. We find no evidence of anomalous neutrino decoherence and determine limits on neutrino-quantum gravity interactions. The constraint on the effective decoherence strength parameter within an energy-independent decoherence model improves on previous limits by a factor of 30. For decoherence effects scaling as E2, our limits are advanced by more than six orders of magnitude beyond past measurements compared with the state of the art. Interactions of atmospheric neutrinos with quantum-gravity-induced fluctuations of the metric of spacetime would lead to decoherence. The IceCube Collaboration constrains such interactions with atmospheric neutrinos.
|
|
| 9. |
- Abbasi, R., et al.
(author)
-
Search for Galactic Core-collapse Supernovae in a Decade of Data Taken with the IceCube Neutrino Observatory
- 2024
-
In: Astrophysical Journal. - : Institute of Physics Publishing (IOPP). - 1538-4357 .- 0004-637X. ; 961:1
-
Journal article (peer-reviewed)abstract
- The IceCube Neutrino Observatory has been continuously taking data to search for O(0.5–10) s long neutrino bursts since 2007. Even if a Galactic core-collapse supernova is optically obscured or collapses to a black hole instead of exploding, it will be detectable via the O(10) MeV neutrino burst emitted during the collapse. We discuss a search for such events covering the time between 2008 April 17 and 2019 December 31. Considering the average data taking and analysis uptime of 91.7% after all selection cuts, this is equivalent to 10.735 yr of continuous data taking. In order to test the most conservative neutrino production scenario, the selection cuts were optimized for a model based on an 8.8 solar mass progenitor collapsing to an O–Ne–Mg core. Conservative assumptions on the effects of neutrino oscillations in the exploding star were made. The final selection cut was set to ensure that the probability to detect such a supernova within the Milky Way exceeds 99%. No such neutrino burst was found in the data after performing a blind analysis. Hence, a 90% C.L. upper limit on the rate of core-collapse supernovae out to distances of ≈25 kpc was determined to be 0.23 yr−1. For the more distant Magellanic Clouds, only high neutrino luminosity supernovae will be detectable by IceCube, unless external information on the burst time is available. We determined a model-independent limit by parameterizing the dependence on the neutrino luminosity and the energy spectrum.
|
|
| 10. |
- Abbasi, R., et al.
(author)
-
Search for 10-1000 GeV Neutrinos from Gamma-Ray Bursts with IceCube
- 2024
-
In: Astrophysical Journal. - : Institute of Physics (IOP). - 1538-4357 .- 0004-637X. ; 964:2
-
Journal article (peer-reviewed)abstract
- We present the results of a search for 10-1000 GeV neutrinos from 2268 gamma-ray bursts (GRBs) over 8 yr of IceCube-DeepCore data. This work probes burst physics below the photosphere where electromagnetic radiation cannot escape. Neutrinos of tens of giga electronvolts are predicted in sub-photospheric collision of free-streaming neutrons with bulk-jet protons. In a first analysis, we searched for the most significant neutrino-GRB coincidence using six overlapping time windows centered on the prompt phase of each GRB. In a second analysis, we conducted a search for a group of GRBs, each individually too weak to be detectable, but potentially significant when combined. No evidence of neutrino emission is found for either analysis. The most significant neutrino coincidence is for Fermi-GBM GRB bn 140807500, with a p-value of 0.097 corrected for all trials. The binomial test used to search for a group of GRBs had a p-value of 0.65 after all trial corrections. The binomial test found a group consisting only of GRB bn 140807500 and no additional GRBs. The neutrino limits of this work complement those obtained by IceCube at tera electronvolt to peta electronvolt energies. We compare our findings for the large set of GRBs as well as GRB 221009A to the sub-photospheric neutron-proton collision model and find that GRB 221009A provides the most constraining limit on baryon loading. For a jet Lorentz factor of 300 (800), the baryon loading on GRB 221009A is lower than 3.85 (2.13) at a 90% confidence level.
|
|
