259 research outputs found
A study of muon neutrino to electron neutrino oscillations in the MINOS experiment
No full textThe observation of neutrino oscillations (neutrino changing from one flavor to another) has provided compelling evidence that the neutrinos have non-zero masses and that leptons mix, which is not part of the original Standard Model of particle physics. The theoretical framework that describes neutrino oscillation involves two mass scales ({Delta}m{sub atm}{sup 2} and {Delta}m{sub sol}{sup 2}), three mixing angles ({theta}{sub 12}, {theta}{sub 23}, and {theta}{sub 13}) and one CP violating phase ({delta}{sub CP}). Both mass scales and two of the mixing angles ({theta}{sub 12} and {theta}{sub 23}) have been measured by many neutrino experiments. The mixing angle {theta}{sub 13}, which is believed to be very small, remains unknown. The current best limit on {theta}13 comes from the CHOOZ experiment: {theta}{sub 13} < 11{sup o} at 90% C.L. at the atmospheric mass scale. {delta}{sub CP} is also unknown today. MINOS, the Main Injector Neutrino Oscillation Search, is a long baseline neutrino experiment based at Fermi National Accelerator Laboratory. The experiment uses a muon neutrino beam, which is measured 1 km downstream from its origin in the Near Detector at Fermilab and then 735 km later in the Far Detector at the Soudan mine. By comparing these two measurements, MINOS can obtain parameters in the atmospheric sector of neutrino oscillations. MINOS has published results on the precise measurement of {Delta}m{sub atm}{sup 2} and {theta}{sub 23} through the disappearance of muon neutrinos in the Far Detector and on a search for sterile neutrinos by looking for a deficit in the number of neutral current interactions seen in the Far Detector. MINOS also has the potential to improve the limit on the neutrino mixing angle {theta}{sub 13} or make the first measurement of its value by searching for an electron neutrino appearance signal in the Far Detector. This is the focus of the study presented in this thesis. We developed a neural network based algorithm to distinguish the electron neutrino signal from background. The most important part of this measurement is the background estimation, which is done through extrapolation. The number of background events is measured at the Near Detector, then extrapolated to the Far Detector. Since different background sources extrapolate differently, some knowledge about the relative contribution from different background sources is necessary. We developed a method that can be used to obtain relative contributions of various background sources from comparison of background rates in the horn-on and horn-off configurations. We also described our effort to improve two aspects of the Monte Carlo simulation which are very important for the {nu}{sub e} appearance analysis: one is the hadronization model in the neutrino-nucleon interactions, the other is the modeling of PMT crosstalk. We performed a blind analysis and examined several sidebands before looking at the signal region. After we opened the box, we observed a 1.4 {sigma} excess of {nu}{sub e}-like events in the Far Detector compared with the number of predicted background events. The excess is well within the statistical fluctuation of the background events. If we interpret the excess as a {nu}{sub e} signal from {nu}{sub {mu}} {yields} {nu}{sub e} oscillation, the best fit sin{sup 2} 2{theta}{sub 13} value is consistent with the CHOOZ limit. However we want to emphasize that our result is consistent with {theta}{sub 13} = 0 at 90% C.L.
Direct Photon Results from CDF
No full textDirect (prompt) photon production is a field of very high interest in hadron colliders. It provides probes to search for new phenomena and to test QCD predictions. In this article, two recent cross-section results for direct photon production using the full CDF Run II data set are presented: diphoton production and photon production in association with a heavy quark
Calibration of Calorimetric Measurement in a Liquid Argon Time Projection Chamber
No full textThe liquid argon time projection chamber provides high-resolution event images and excellent calorimetric resolution for studying neutrino physics and searching for beyond-standard-model physics. In this article, we review the main physics processes that affect detector response, including the electronics and field responses, space charge effects, electron attachment to impurities, diffusion, and recombination. We describe methods to measure those effects, which are used to calibrate the detector response and convert the measured raw analog-to-digital converter (ADC) counts into the original energy deposition
SEARCH FOR ν<sub>μ</sub>→ν<sub>e</sub> OSCILLATIONS IN THE MINOS EXPERIMENT
No full text The MINOS experiment uses the NuMI νμ beam to make precise measurements of neutrino flavor oscillations in the "atmospheric" neutrino sector. MINOS can also probe the yet-unknown neutrino mixing angle θ13 by searching for a νe appearance signal in the νμ beam. This paper reviews the techniques developed for the first νe appearance analysis in MINOS. </jats:p
Jia li yi jie
No full text朱熹編 ; 丘濬輯.In 1 case.框22.1x13.9公分, 9行20字, 小字雙行同, 白口, 四周單邊, 單白魚尾, 版心上鐫"家禮儀節", 中鐫卷次及小題, 下鐫葉次.前有楊廷筠序, 方大鎮序, 杜承式序, 錢時序, 成化甲午[1474]丘濬序.Zhu Xi bian ; Qiu Jun ji.Kuang 22.1 x 13.9 gong fen, 9 hang 20 zi, xiao zi shuang hang tong, bai kou, si zhou dan bian, dan bai yu wei, ban xin shang juan "Jia li yi jie", zhong juan juan ci ji xiao ti, xia juan ye ci.Qian you Yang Tingjun xu, Fang Dazhen xu, Du Chengshi xu, Qian Shi xu, Chenghua jia wu [1474] Qiu Jun xu
A deep-learning based waveform region-of-interest finder for the liquid argon time projection chamber
No full textParallel Flash Talk at the
"XIX International Workshop on Neutrino Telescopes"
on line - 18-26 February, 2021On behalf of the ArgoNeuT Collaboration
Fermilab-Slides-21-007-ND-SCD-
Estimation of low-occurrence strong wind speed in a realistic urban area using statistical methods
No full text修士（工学）Master of Engineerin
Spatial and temporal variations in air temperature and precipitation in the Chinese Himalayas during the 1971–2007
No full text
NP04 2021 Annual Report to the CERN-SPSC
No full textJuly 2020 marked the end of a two year successful operation of the ProtoDUNE Single Phase Liquid Argon TPC (NP04) exposed to charged particle beams and cosmic rays in the CERN-EHN1 experimental area. The present report focuses on the results of the data analysis achieved up to now and on the understanding of the detector performance. An overview of the decommissioning phase is also given as well as the motivation, the plans and a tentative schedule for NP04 Phase-II
- …
