scholarly journals The MicroBooNE Single-Photon Low-Energy Excess Search

2020 ◽  
Author(s):  
Sowjanya Gollapinni ◽  
Georgia Karagiorgi ◽  
Mark Lonegran ◽  
William Louis ◽  
Richard Van De Water ◽  
...  
Keyword(s):  
Single Photon ◽  
Low Energy ◽  
Energy Excess

scholarly journals Erratum to: A new analysis of the MiniBooNE low-energy excess

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
C. Giunti ◽  
A. Ioannisian ◽  
G. Ranucci
Keyword(s):  
Low Energy ◽  
Correct Version ◽  
Energy Excess

After publication we discovered that some entries in table 2 and the corresponding contours in figures 3 and 4 have been misprinted. We provide here the correct version of table 2 and figures 3 and 4. The discussion and conclusions in the text of the paper remain unchanged.

scholarly journals Spurious poles in the scattering of electric and magnetic charges

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
John Terning ◽  
Christopher B. Verhaaren
Keyword(s):  
Perturbation Theory ◽  
Scattering Amplitudes ◽  
Pair Production ◽  
Magnetic Particles ◽  
Single Photon ◽  
Low Energy ◽  
Magnetic Interactions ◽  
Parity Conservation ◽  
Non Local ◽  
The Way

Abstract Theories with both electric and magnetic charges (“mutually non-local” theories) have several major obstacles to calculating scattering amplitudes. Even when the interaction arises through the kinetic mixing of two, otherwise independent, U(1)’s, so that all low-energy interactions are perturbative, difficulties remain: using a self-dual, local formalism leads to spurious poles at any finite order in perturbation theory. Correct calculations must show how the spurious poles cancel in observable scattering amplitudes. Consistency requires that one type of charge is confined as a result of one of the U(1)’s being broken. Here we show how the constraints of confinement and parity conservation on observable processes manages to cancel the spurious poles in scattering and pair production amplitudes, paving the way for systematic studies of the experimental signatures of “dark” electric-magnetic processes. Along the way we demonstrate some novel effects in electric-magnetic interactions, including that the amplitude for single photon production of magnetic particles by electric particles vanishes.

scholarly journals Studying the low-energy excess in cosmic-ray iron: a possible evidence of a massive supernova activity in the solar neighborhood via primary 60Fe

2021 ◽  
Author(s):  
Nicolo Masi ◽  
M. J. Boschini ◽  
S. Della Torre ◽  
M. Gervasi ◽  
D. Grandi ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
Solar Neighborhood ◽  
Low Energy ◽  
Energy Excess

scholarly journals The EIGER detector for low-energy electron microscopy and photoemission electron microscopy

2017 ◽  
Vol 24 (5) ◽  
pp. 963-974 ◽  
Author(s):  
G. Tinti ◽  
H. Marchetto ◽  
C. A. F. Vaz ◽  
A. Kleibert ◽  
M. Andrä ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Dynamic Range ◽  
Single Photon ◽  
Low Energy ◽  
Energy Electron ◽  
Frame Rate ◽  
Pixel Detector ◽  
Photoemission Electron Microscopy ◽  
Low Energy Electron ◽  
Photoemission Electron

EIGER is a single-photon-counting hybrid pixel detector developed at the Paul Scherrer Institut, Switzerland. It is designed for applications at synchrotron light sources with photon energies above 5 keV. Features of EIGER include a small pixel size (75 µm × 75 µm), a high frame rate (up to 23 kHz), a small dead-time between frames (down to 3 µs) and a dynamic range up to 32-bit. In this article, the use of EIGER as a detector for electrons in low-energy electron microscopy (LEEM) and photoemission electron microscopy (PEEM) is reported. It is demonstrated that, with only a minimal modification to the sensitive part of the detector, EIGER is able to detect electrons emitted or reflected by the sample and accelerated to 8–20 keV. The imaging capabilities are shown to be superior to the standard microchannel plate detector for these types of applications. This is due to the much higher signal-to-noise ratio, better homogeneity and improved dynamic range. In addition, the operation of the EIGER detector is not affected by radiation damage from electrons in the present energy range and guarantees more stable performance over time. To benchmark the detector capabilities, LEEM experiments are performed on selected surfaces and the magnetic and electronic properties of individual iron nanoparticles with sizes ranging from 8 to 22 nm are detected using the PEEM endstation at the Surface/Interface Microscopy (SIM) beamline of the Swiss Light Source.

Low energy excess magnetic states in terbium metaphosphate glass

1999 ◽  
Vol 79 (11-12) ◽  
pp. 2121-2127
Author(s):  
T. Brennan ◽  
G. A. Saunders ◽  
B. D. R. Rainford ◽  
R. Eccleston ◽  
G. Carini ◽  
...  
Keyword(s):  
Low Energy ◽  
Energy Excess ◽  
Magnetic States

Low energy excess magnetic states in terbium metaphosphate glass

1999 ◽  
Vol 79 (11-12) ◽  
pp. 2121-2127 ◽  
Author(s):  
T. Brennan, G. A. Saunders, B. D. R. R
Keyword(s):  
Low Energy ◽  
Energy Excess ◽  
Magnetic States

scholarly journals Multiple hot-carrier collection in photo-excited graphene Moiré superlattices

2016 ◽  
Vol 2 (5) ◽  
pp. e1600002 ◽  
Author(s):  
Sanfeng Wu ◽  
Lei Wang ◽  
You Lai ◽  
Wen-Yu Shan ◽  
Grant Aivazian ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Single Photon ◽  
Power Conversion ◽  
Low Energy ◽  
Zero Bias ◽  
Hot Carrier ◽  
Emergent Phenomenon ◽  
Carrier Collection ◽  
Superlattice Structures ◽  
Standard Limit

In conventional light-harvesting devices, the absorption of a single photon only excites one electron, which sets the standard limit of power-conversion efficiency, such as the Shockley-Queisser limit. In principle, generating and harnessing multiple carriers per absorbed photon can improve efficiency and possibly overcome this limit. We report the observation of multiple hot-carrier collection in graphene/boron-nitride Moiré superlattice structures. A record-high zero-bias photoresponsivity of 0.3 A/W (equivalently, an external quantum efficiency exceeding 50%) is achieved using graphene’s photo-Nernst effect, which demonstrates a collection of at least five carriers per absorbed photon. We reveal that this effect arises from the enhanced Nernst coefficient through Lifshtiz transition at low-energy Van Hove singularities, which is an emergent phenomenon due to the formation of Moiré minibands. Our observation points to a new means for extremely efficient and flexible optoelectronics based on van der Waals heterostructures.

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