Search for eV Sterile Neutrinos - The Stereo Experiment

In the recent years, major milestones in neutrino physics were accomplished at nuclear reactors: the smallest neutrino mixing angle $\theta_{13}$ was determined with high precision and the emitted antineutrino spectrum was measured at unprecedented resolution. However, two anomalies, the first one related to the absolute flux and the second one to the spectral shape, have yet to be solved. The flux anomaly is known as the Reactor Antineutrino Anomaly and could be caused by the existence of a light sterile neutrino participating in the neutrino oscillation phenomenon. Introducing a sterile state implies the presence of a fourth mass eigenstate, global fits favour oscillation parameters around $\sin^2({2\theta}) \approx 0.09$ and $\Delta m^2 \approx 1\,\mathrm{eV}^2$. The Stereo experiment was built to finally solve this puzzle. It is one of the first running experiments built to search for eV sterile neutrinos and takes data since end of 2016 at ILL Grenoble (France). At a short baseline of 10 metres, it measures the antineutrino flux and spectrum emitted by a compact research reactor. The segmentation of the detector in six target cells allows for measurements of the neutrino spectrum at multiple baselines. An active-sterile flavour oscillation could be unambiguously detected, as it distorts the spectral shape of each cell's measurement differently. This contribution gives an overview on the Stereo experiment, along with details on the detector design, detection principle and the current status of data analysis.Comment: Proceedings for EPS-HEP 2017, European Physical Society Conference on High Energy Physics (5-12 July 2017), Venice, Ital

Neutron Detection Uncertainties in the θ₁₃ Analysis of the Double Chooz Experiment

The reactor antineutrino experiment Double Chooz aims to provide a precise measurement of the neutrino mixing angle θ₁₃. In the analysis with one detector, accuracy in the predicted neutrino spectrum from simulation is a necessity with regard to normalization and energy shape. The detection efficiency of neutron events, which are part of the coincidence signal created by neutrinos, introduce the largest uncertainty contribution of the normalization of the experiment related to the signal detection. In order to accomplish a matching of the efficiencies observed in data and simulation, a correction of the Monte Carlo normalization and an associated systematic uncertainty are inputs in the θ₁₃ analysis. Calibration source deployments in the inner two detector volumes allow for a measurement of the neutron detection efficiency using ²⁵²Cf fission neutrons. New methods enable to compute the correction integrated over the whole volume and the corresponding uncertainty of the selection cut related efficiency. With these revised approaches a factor two improvement in the detection efficiency uncertainty was achieved. The correction of the neutron capture fraction – the capture fraction quantifies the proportion of captures on a particular element – is evaluated and tested for its robustness. Furthermore, a crosscheck of this quantity is discussed using neutrons produced by cosmic muon spallation. Finally, the uncertainty on border effects, emerging from neutron migration at the fiducial volume boundaries, is estimated by means of different Monte Carlo configurations with varying parameters and neutron physics modelings

Afterpulse Measurements of R7081 Photomultipliers for the Double Chooz Experiment

We present the results of afterpulse measurements performed as qualification test for 473 inner detector photomultipliers of the Double Chooz experiment. The measurements include the determination of a total afterpulse occurrence probability as well as an average time distribution of these pulses. Additionally, more detailed measurements with different light sources and simultaneous charge and timing measurements were performed with a few photomultipliers to allow a more detailed understanding of the effect. The results of all measurements are presented and discussed

Evaluation of the cost and effectiveness of diverse recruitment methods for a genetic screening study

Purpose: Recruitment of participants from diverse backgrounds is crucial to the generalizability of genetic research, but has proven challenging. We retrospectively evaluated recruitment methods used for a study on return of genetic results. Methods: The costs of study design, development, and participant enrollment were calculated, and the characteristics of the participants enrolled through the seven recruitment methods were examined. Results: A total of 1118 participants provided consent, a blood sample, and questionnaire data. The estimated cost across recruitment methods ranged from $579 to$1666 per participant and required a large recruitment team. Recruitment methods using flyers and staff networks were the most cost-efficient and resulted in the highest completion rate. Targeted sampling that emphasized the importance of Latino/a participation, utilization of translated materials, and in-person recruitments contributed to enrolling a demographically diverse sample. Conclusions: Although all methods were deployed in the same hospital or neighborhood and shared the same staff, each recruitment method was different in terms of cost and characteristics of the enrolled participants, suggesting the importance of carefully choosing the recruitment methods based on the desired composition of the final study sample. This analysis provides information about the effectiveness and cost of different methods to recruit adults for genetic research

Theologie und Vergangenheitsbewältigung VI. Diskurse über „Form“, „Gestalt“ und „Stil“ in den 20er und 30er Jahren

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Trading System Analysis and Marketing Margins for Tuna, Cakalang, and Tongkol at Fish Auction Place (TPI) Kuala Idi, East Aceh District

Marketing of fishery products must be carried out efficiently so that fishermen and consumers are not harmed. The purpose of this study was to analyze the marketing system, margin value, fisherman's share for skipjack, tuna and tuna in TPI Kuala Idi. Determination of respondents using purposive sampling method. The results of the study were obtained for Cakalang fish, the total marketing margin on marketing channel II was greater, namely Rp. 5,800 and channel I obtained the highest Df, namely 89%. For Tuna, the total marketing margin in marketing channel II is greater, namely Rp. 6,400 and channel I obtains the highest Df, namely 86%. For tuna, the total marketing margin on marketing channel II was greater, namely IDR 5,800 and channel I obtained the highest Df, namely 87%. From the results of Fisherman's Share calculations, the three marketing channels above the percentage share received by fishermen from TPI is 89% and is the largest percentage of other marketing calculations. It can be concluded that the marketing agency TPI Kuala Idi, East Aceh District plays an important role in the share of the results received by fishermen.Pemasaran hasil perikanan harus dilakukan secara efisien agar nelayan dan konsumen tidak dirugikan. Tujuan dari penelitian ini adalah untuk menganalisis sistem pemasaran, nilai marjin, fisherman’s share pada ikan cakalang, tuna, dan tongkol di TPI Kuala Idi. Penentuan responden dengan menggunakan metode purposive sampling. Hasil penelitian diperoleh pada ikan Cakalang, total margin pemasaran pada saluran pemasaran II lebih besar yaitu Rp 5.800 dan saluran I memperoleh Df tertinggi yaitu 89%. Pada ikan Tuna, bahwa total margin pemasaran pada saluran pemasaran II lebih besar yaitu Rp 6.400 dan saluran I memperoleh Df tertinggi yaitu 86%. Pada ikan Tongkol total margin pemasaran pada saluran pemasaran II lebih besar yaitu Rp 5.800 dan saluran I memperoleh Df tertinggi yaitu 87%. Dari hasil perhitungan Fisherman’s Share ketiga saluran pemasaran diatas persentase bagian yang diterima nelayan dari TPI sebesar 89% dan merupakan persentase terbesar dari perhitungan pemasaran lainnya. Dapat disimpulkan lembaga pemasaran TPI Kuala Idi, Kabupaten Aceh Timur memegang peranan penting dalam bagian hasil yang diterima oleh nelayan

Search for light sterile neutrinos with the STEREO experiment

International audienceThe stereo experiment is searching for a non-standard oscillation in the propagation of anti-neutrinos produced by a nuclear reactor which could be the sign for the existence of a sterile state of eV mass and the origin of the reactor anti-neutrino anomaly. In this paper, results from 66 days of reactor turned on and 138 days of reactor turned off are reported excluding large amplitude oscillations. A special focus is put on the data analysis and studies of correlated backgrounds. In particular the origin of the correlated background measured in reactor turned off periods is discussed. This background mainly originates from neutrons produced by cosmic radiation

Search for light sterile neutrinos with the STEREO experiment

The stereo experiment is searching for a non-standard oscillation in the propagation of anti-neutrinos produced by a nuclear reactor which could be the sign for the existence of a sterile state of eV mass and the origin of the reactor anti-neutrino anomaly. In this paper, results from 66 days of reactor turned on and 138 days of reactor turned off are reported excluding large amplitude oscillations. A special focus is put on the data analysis and studies of correlated backgrounds. In particular the origin of the correlated background measured in reactor turned off periods is discussed. This background mainly originates from neutrons produced by cosmic radiation