620 research outputs found
Optimizing multi-dimensional terahertz imaging analysis for colon cancer diagnosis
Peer reviewedPublisher PD
Globular Cluster Systems in Brightest Cluster Galaxies. III: Beyond Bimodality
We present new deep photometry of the rich globular cluster (GC) systems
around the Brightest Cluster Galaxies UGC 9799 (Abell 2052) and UGC 10143
(Abell 2147), obtained with the HST ACS and WFC3 cameras. For comparison, we
also present new reductions of similar HST/ACS data for the Coma supergiants
NGC 4874 and 4889. All four of these galaxies have huge cluster populations (to
the radial limits of our data, comprising from 12000 to 23000 clusters per
galaxy). The metallicity distribution functions (MDFs) of the GCs can still be
matched by a bimodal-Gaussian form where the metal-rich and metal-poor modes
are separated by ~0.8 dex, but the internal dispersions of each mode are so
large that the total MDF becomes very broad and nearly continuous from [Fe/H] =
-2.4 to Solar. There are, however, significant differences between galaxies in
the relative numbers of \emph{metal-rich} clusters, suggesting that they
underwent significantly different histories of mergers with massive, gas-rich
halos. Lastly, the proportion of metal-poor GCs rises especially rapidly
outside projected radii R > 4 R_eff, suggesting the importance of accreted
dwarf satellites in the outer halo. Comprehensive models for the formation of
GCs as part of the hierarchical formation of their parent galaxies will be
needed to trace the systematic change in structure of the MDF with galaxy mass,
from the distinctly bimodal form in smaller galaxies up to the broad continuum
that we see in the very largest systems.Comment: In press for Astrophysical Journa
A New Technique for Finding Needles in Haystacks: A Geometric Approach to Distinguishing Between a New Source and Random Fluctuations
We propose a new test statistic based on a score process for determining the
statistical significance of a putative signal that may be a small perturbation
to a noisy experimental background. We derive the reference distribution for
this score test statistic; it has an elegant geometrical interpretation as well
as broad applicability. We illustrate the technique in the context of a model
problem from high-energy particle physics. Monte Carlo experimental results
confirm that the score test results in a significantly improved rate of signal
detection.Comment: 5 pages, 4 figure
Direct CP violation for decay in QCD factorization
In the framework of QCD factorization, based on the first order of isospin
violation, we study direct CP violation in the decay of including the effect of
mixing. We find that the CP violating asymmetry is large via
mixing mechanism when the invariant mass of the
pair is in the vicinity of the resonance. For the decay of
, the maximum
CP violating asymmetries can reach about 46%. We also discuss the possibility
to observe the predicted CP violating asymmetries at the LHC
Distribution and dynamics of nitrogen and microbial plankton in southern Lake Michigan during spring transition 1999â2000
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95655/1/jgrc9187.pd
Statistical Mechanics of the Quantum K-Satisfiability problem
We study the quantum version of the random -Satisfiability problem in the
presence of the external magnetic field applied in the transverse
direction. We derive the replica-symmetric free energy functional within static
approximation and the saddle-point equation for the order parameter: the
distribution of functions of magnetizations. The order parameter is
interpreted as the histogram of probability distributions of individual
magnetizations. In the limit of zero temperature and small transverse fields,
to leading order in magnetizations become relevant in
addition to purely classical values of . Self-consistency
equations for the order parameter are solved numerically using Quasi Monte
Carlo method for K=3. It is shown that for an arbitrarily small
quantum fluctuations destroy the phase transition present in the classical
limit , replacing it with a smooth crossover transition. The
implications of this result with respect to the expected performance of quantum
optimization algorithms via adiabatic evolution are discussed. The
replica-symmetric solution of the classical random -Satisfiability problem
is briefly revisited. It is shown that the phase transition at T=0 predicted by
the replica-symmetric theory is of continuous type with atypical critical
exponents.Comment: 35 pages, 23 figures; changed abstract, improved discussion in the
introduction, added references, corrected typo
Recent AEM Case Study Examples of a Full Waveform Time-Domain System for Near-Surface and Groundwater Applications
Early time or high frequency airborne electromagnetic data (AEM) are desirable for shallow sounding or mapping of resistive areas but this poses difficulties due to a variety of issues, such as system bandwidth, system calibration and parasitic loop capacitance. In an effort to address this issue, a continued system design strategy, aimed at improving its early-channel VTEM data, has achieved fully calibrated, quantitative measurements closer to the transmitter current turn-off, while maintaining reasonably optimal deep penetration characteristics. The new design implementation, known as âFull Waveformâ VTEM was previously described by Legault et al. (2012). This paper presents some case-study examples of a Full Waveform helicopter time-domain EM system for near-surface application
Search for Narrow NNpi Resonances in Exclusive p p -> p p pi+ pi- Measurements
Narrow structures in the range of a few MeV have been searched for in p p pi+
and p p pi- invariant mass spectra obtained from exclusive measurements of the
p p -> p p pi+ pi- reaction at Tp = 725, 750 and 775 MeV using the PROMICE/WASA
detector at CELSIUS. The selected reaction is particularily well suited for the
search for NN and / or N Delta decoupled dibaryon resonances. Except for a
possible fluctuation at 2087 MeV/c^2 in Mpppi- no narrow structures could be
identified neither in Mpppi+ nor in Mpppi- on the 3 sigma level of statistical
significance, giving an upper limit (95% C.L.) for dibaryon production in this
reaction of sigma < 20 nb for 2020 MeV/c^2 < m(dibaryon) < 2085 MeV/c^2Comment: 3 pages, 4 figure
Lake Erie hypoxia prompts CanadaâU.S. study
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95631/1/eost15589.pd
Development of recurrent coastal plume in Lake Michigan observed for first time
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94637/1/eost11132.pd
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