scholarly journals First observation of low energy electron neutrinos in a liquid argon time projection chamber

2017 ◽  
Vol 95 (7) ◽  
Author(s):  
R. Acciarri ◽  
C. Adams ◽  
J. Asaadi ◽  
B. Baller ◽  
T. Bolton ◽  
...  
2009 ◽  
Vol 24 (24) ◽  
pp. 1937-1942 ◽  
Author(s):  
FRANCESCO GIACOSA ◽  
RALF HOFMANN

In this letter we investigate the possible emission of low-energy electron neutrinos and electron–positron pairs of anomalously large multiplicity in close-to-central pp collisions at LHC. The scenario is based on confining SU(2) Yang–Mills dynamics of Hagedorn temperature ~ me = 511 keV being responsible for the emergence of the lightest lepton family and the weak interactions of the Standard Model. Although cut off by LHC's detectors these electron–positron bursts would be seen indirectly by a large defect energy and thus an anomalously strong decrease of events with interesting high-energy secondaries for increasing [Formula: see text]. This is because the formation of superconducting (preconfining) SU(2) hot-spots "steals" a large fraction of [Formula: see text] subsequently transferring it to a thermal spectrum of electron neutrinos, electrons, and positrons liberated through evaporation. We thus propose the detection of electrons and positrons of kinetic energy ~ me and photons of energy ~ 2me.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
C. E. Aalseth ◽  
P. Agnes ◽  
A. Alton ◽  
K. Arisaka ◽  
D. M. Asner ◽  
...  

Although the existence of dark matter is supported by many evidences, based on astrophysical measurements, its nature is still completely unknown. One major candidate is represented by weakly interacting massive particles (WIMPs), which could in principle be detected through their collisions with ordinary nuclei in a sensitive target, producing observable low-energy (<100 keV) nuclear recoils. The DarkSide program aims at the WIPMs detection using a liquid argon time projection chamber (LAr-TPC). In this paper we quickly review the DarkSide program focusing in particular on the next generation experiment DarkSide-G2, a 3.6-ton LAr-TPC. The different detector components are described as well as the improvements needed to scale the detector from DarkSide-50 (50 kg LAr-TPC) up to DarkSide-G2. Finally, the preliminary results on background suppression and expected sensitivity are presented.


2022 ◽  
Vol 17 (01) ◽  
pp. P01018
Author(s):  
R. Acciarri ◽  
B. Baller ◽  
V. Basque ◽  
C. Bromberg ◽  
F. Cavanna ◽  
...  

Abstract The liquid argon time projection chamber (LArTPC) detector technology has an excellent capability to measure properties of low-energy neutrinos produced by the sun and supernovae and to look for exotic physics at very low energies. In order to achieve those physics goals, it is crucial to identify and reconstruct signals in the waveforms recorded on each TPC wire. In this paper, we report on a novel algorithm based on a one-dimensional convolutional neural network (CNN) to look for the region-of-interest (ROI) in raw waveforms. We test this algorithm using data from the ArgoNeuT experiment in conjunction with an improved noise mitigation procedure and a more realistic data-driven noise model for simulated events. This deep-learning ROI finder shows promising performance in extracting small signals and gives an efficiency approximately twice that of the traditional algorithm in the low energy region of ∼0.03–0.1 MeV. This method offers great potential to explore low-energy physics using LArTPCs.


Author(s):  
Bertholdand Senftinger ◽  
Helmut Liebl

During the last few years the investigation of clean and adsorbate-covered solid surfaces as well as thin-film growth and molecular dynamics have given rise to a constant demand for high-resolution imaging microscopy with reflected and diffracted low energy electrons as well as photo-electrons. A recent successful implementation of a UHV low-energy electron microscope by Bauer and Telieps encouraged us to construct such a low energy electron microscope (LEEM) for high-resolution imaging incorporating several novel design features, which is described more detailed elsewhere.The constraint of high field strength at the surface required to keep the aberrations caused by the accelerating field small and high UV photon intensity to get an improved signal-to-noise ratio for photoemission led to the design of a tetrode emission lens system capable of also focusing the UV light at the surface through an integrated Schwarzschild-type objective. Fig. 1 shows an axial section of the emission lens in the LEEM with sample (28) and part of the sample holder (29). The integrated mirror objective (50a, 50b) is used for visual in situ microscopic observation of the sample as well as for UV illumination. The electron optical components and the sample with accelerating field followed by an einzel lens form a tetrode system. In order to keep the field strength high, the sample is separated from the first element of the einzel lens by only 1.6 mm. With a numerical aperture of 0.5 for the Schwarzschild objective the orifice in the first element of the einzel lens has to be about 3.0 mm in diameter. Considering the much smaller distance to the sample one can expect intense distortions of the accelerating field in front of the sample. Because the achievable lateral resolution depends mainly on the quality of the first imaging step, careful investigation of the aberrations caused by the emission lens system had to be done in order to avoid sacrificing high lateral resolution for larger numerical aperture.


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