1,012 research outputs found
Simultaneous measurement and reconstruction tailoring for quantitative phase imaging
We propose simultaneous measurement and reconstruction tailoring (SMaRT) for quantitative phase imaging; it is a joint optimization approach to inverse problems wherein minimizing the expected end-to-end error yields optimal design parameters for both the measurement and reconstruction processes. Using simulated and experimentally-collected data for a specific scenario, we demonstrate that optimizing the design of the two processes together reduces phase reconstruction error over past techniques that consider these two design problems separately. Our results suggest at times surprising design principles, and our approach can potentially inspire improved solution methods for other inverse problems in optics as well as the natural sciences.Singapore-MIT Alliance. BioSystems and Micromechanics (BioSyM) Inter-Disciplinary Research GroupSingapore. National Research Foundatio
Searching for Majorana Neutrinos at a Same-Sign Muon Collider
Majorana properties of neutrinos have long been a focus in the pursuit of
possible new physics beyond the standard model, which has motivated lots of
dedicated theoretical and experimental studies. A future same-sign muon
collider is an ideal platform to search for Majorana neutrinos through the
Lepton Number Violation process. Specifically, this t-channel kind of process
is less kinematically suppressed and has a good advantage in probing Majorana
neutrinos at high mass regions up to 10 TeV. In this paper, we perform a
detailed fast Monte Carlo simulation study through examining three different
final states: 1) pure-leptonic state with electrons or muons, 2) semi-leptonic
state, and 3) pure-hadronic state in the resolved or merged categories.
Furthermore, we perform a full simulation study on the pure-leptonic final
state to validate our fast simulation results.Comment: 15 pages, 8 figure
A Comparative Study of Z mediated Charged Lepton Flavor Violation at future lepton colliders
Charged lepton flavor violation (CLFV) represents a transition between
charged leptons of different generations that violates lepton flavor
conservation, which is a clear signature of possible new physics beyond the
standard model. By exploiting a typical example model of extra Z
gauge boson, we perform a detailed comparative study on CLFV searches at
several future lepton colliders, including a 240 GeV electron-positron collider
and a TeV scale muon collider. Based on detailed signal and background
Monte-Carlo studies with fast detector simulations, we derive the potentials in
searching for Z mediated CLFV couplings with , and
of different future colliders. The results are compared with the
current limits set by either low-energy experiments or the high-energy LHC
experiments. We find that the sensitivity of the related CLFV coupling
strength at future lepton colliders will be significantly improved comparing
with the current best constraints.Comment: 11 pages, 5 figure
The physics case for a neutrino lepton collider in light of the CDF W mass measurement
We propose a neutrino lepton collider where the neutrino beam is generated
from TeV scale muon decays. Such a device would allow for a precise measurement
of the W mass based on single W production: nu l to W. Although it is
challenging to achieve high instantaneous luminosity with such a collider, we
find that a total luminosity of 0.1/fb can already yield competitive physics
results. In addition to a W mass measurement, a rich variety of physics goals
could be achieved with such a collider, including W boson precision
measurements, heavy leptophilic gauge boson searches, and anomalous Znunu
coupling searches. A neutrino lepton collider is both a novel idea in itself,
and may also be a useful intermediate step, with less muon cooling required,
towards the muon-muon collider already being pursued by the energy frontier
community. A neutrino neutrino or neutrino proton collider may also be
interesting future options for the high energy frontier.Comment: 4 pages, 5 plots, accepted version by IJMP
Room temperature deposition of Al-doped ZnO films on quartz substrates by radio-frequency magnetron sputtering and effects of thermal annealing
High-quality Al-doped zinc oxide (AZO) thin films have been deposited on quartz substrates by radio-frequency magnetron sputtering at room temperature for thin film solar cell applications as transparent conductive oxide (TCO) electrode layers. Effects of post-deposition annealing treatment in pure nitrogen and nitrogen/hydrogen atmosphere have been investigated. Annealing treatments were carried out from 300 degrees C to 600 degrees C for compatibility with typical optoelectronic device fabrication processes. A series of characterization techniques, including X-ray diffraction, scanning electron microscopy, Hall, optical transmission, and X-ray photoelectron spectroscopy has been employed to study these AZO materials. It was found that there were significant changes in crystallinity of the films, resistivity increased from 4.60 x 10(-4) to 4.66 x 10(-3) Omega cm and carrier concentration decreased from 8.68 x 10(20) to 2.77 x 10(20) cm(-3) when annealing in 400 degrees C pure nitrogen. Whereas there were no significant changes in electrical and optical properties of the AZO films when annealing in 300-500 degrees C nitrogen/ hydrogen atmosphere, the electrical stability of the AZO films during the hydrogen treatment is attributed to both desorption of adsorbed oxygen from the grain boundaries and production of additional oxygen vacancies that act as donor centers in the films by removal of oxygen from the ZnO matrix. These results demonstrated that the AZO films are stably suited for TCO electrodes in display devices and solar cells. (C) 2010 Elsevier B.V. All rights reserved
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