8,699 research outputs found
Supermassive Black Holes with High Accretion Rates in Active Galactic Nuclei. V. A New Size-Luminosity Scaling Relation for the Broad-Line Region
This paper reports results of the third-year campaign of monitoring
super-Eddington accreting massive black holes (SEAMBHs) in active galactic
nuclei (AGNs) between 2014-2015. Ten new targets were selected from quasar
sample of Sloan Digital Sky Survey (SDSS), which are generally more luminous
than the SEAMBH candidates in last two years. H lags () in five of the 10 quasars have been successfully measured in this
monitoring season. We find that the lags are generally shorter, by large
factors, than those of objects with same optical luminosity, in light of the
well-known relation. The five quasars have
dimensionless accretion rates of . Combining
measurements of the previous SEAMBHs, we find that the reduction of H
lags tightly depends on accretion rates, , where
is the H lag from the normal relation.
Fitting 63 mapped AGNs, we present a new scaling relation for the broad-line
region: ,
where is 5100 \AA\ continuum
luminosity, and coefficients of lt-d,
, and
. This relation is applicable to
AGNs over a wide range of accretion rates, from to .
Implications of this new relation are briefly discussed.Comment: 15 pages, 9 figures, 5 table, accepted for publication in The
Astrophysical Journa
Two Photon Decays of from Lattice QCD
We present an exploratory lattice study for the two-photon decay of
using twisted mass lattice QCD gauge configurations generated by the
European Twisted Mass Collaboration. Two different lattice spacings of
fm and fm are used in the study, both of which are of
physical size of 2. The decay widths are found to be KeV for the
coarser lattice and KeV for the finer lattice respectively where the
errors are purely statistical. A naive extrapolation towards the continuum
limit yields KeV which is smaller than the previous
quenched result and most of the current experimental results. Possible reasons
are discussed.Comment: 13 pages, 7 figures; matches the published versio
Machine learning-based volume diagnosis
In this paper, a novel diagnosis method is proposed. The proposed technique uses machine learning techniques instead of traditional cause-effect and/or effect-cause analysis. The proposed technique has several advantages over traditional di-agnosis methods, especially for volume diagnosis. In the pro-posed method, since the time consuming diagnosis process is reduced to merely evaluating several decision functions, run time complexity is much lower than traditional diagnosis meth-ods. The proposed technique can provide not only high reso-lution diagnosis but also statistical data by classifying defec-tive chips according to locations of their defects. Even with highly compressed output responses, the proposed diagnosis technique can correctly locate defect locations for most defec-tive chips. The proposed technique correctly located defects for more than 90 % (86 %) defective chips at 50x (100x) out-put compaction. Run time for diagnosing a single simulated defect chip was only tens of milli-seconds.
NUMERICAL DISTRIBUTION SIMULATION OF TYPHOONS’ WAVE ENERGY IN THE TAIWAN STRAIT AND ITS ADJACENT WATERS
As new energy technologies boom in recent years, marine renewable energy, especially wave power is one potential trend. However, few relevant studies focus on extreme sea conditions. In this paper, a numerical model of typhoon waves in the Taiwan Strait is established based on the third-generation ocean wave model SWAN and then calculated by the wave energy empirical equation. Typhoon No. 200808 Fung-wong, strong typhoon No. 200815 Jangmi and strong typhoon No. 201808 Maria are used for verification and analysis. Finally, the results show that most concentrated wave energy values are more than 300 kW/m for typhoon and more than 900 kW/m for strong typhoons, over 60 times and 180 times the annual average (5 kW/m) in the Chinese sea area, respectively. In terms of other locations, corresponding values are more than 50 kW/m and over 100 kW/m. Therefore, typhoons’ wave energy is certainly a huge asset if fully utilized
A Unified Approach to the Classical Statistical Analysis of Small Signals
We give a classical confidence belt construction which unifies the treatment
of upper confidence limits for null results and two-sided confidence intervals
for non-null results. The unified treatment solves a problem (apparently not
previously recognized) that the choice of upper limit or two-sided intervals
leads to intervals which are not confidence intervals if the choice is based on
the data. We apply the construction to two related problems which have recently
been a battle-ground between classical and Bayesian statistics: Poisson
processes with background, and Gaussian errors with a bounded physical region.
In contrast with the usual classical construction for upper limits, our
construction avoids unphysical confidence intervals. In contrast with some
popular Bayesian intervals, our intervals eliminate conservatism (frequentist
coverage greater than the stated confidence) in the Gaussian case and reduce it
to a level dictated by discreteness in the Poisson case. We generalize the
method in order to apply it to analysis of experiments searching for neutrino
oscillations. We show that this technique both gives correct coverage and is
powerful, while other classical techniques that have been used by neutrino
oscillation search experiments fail one or both of these criteria.Comment: 40 pages, 15 figures. Changes 15-Dec-99 to agree more closely with
published version. A few small changes, plus the two substantive changes we
made in proof back in 1998: 1) The definition of "sensitivity" in Sec. V(C).
It was inconsistent with our actual definition in Sec. VI. 2) "Note added in
proof" at end of the Conclusio
Evidence for at center-of-mass energies from 4.009 to 4.360 GeV
Using data samples collected at center-of-mass energies of =
4.009, 4.230, 4.260, and 4.360 GeV with the BESIII detector operating at the
BEPCII collider, we perform a search for the process
and find evidence for and
with statistical significances of 3.0 and
3.4, respectively. The Born cross sections
, as well as their upper limits at the
90% confidence level are determined at each center-of-mass energy.Comment: 8 pages, 7 figures, 3 table
Observation of decays into vector meson pairs , , and
Decays of to vector meson pairs , and
are observed for the first time using
\psip events accumulated at the BESIII detector at the BEPCII
collider. The branching fractions are measured to be , , and , for , , and ,
respectively. The observation of decays into a pair of vector
mesons , and indicates that the hadron
helicity selection rule is significantly violated in decays. In
addition, the measurement of gives the rate of doubly
OZI-suppressed decay. Branching fractions for and
decays into other vector meson pairs are also measured with improved precision.Comment: 4 pages, 2 figure
Centrality categorization for R_{p(d)+A} in high-energy collisions
High-energy proton- and deuteron-nucleus collisions provide an excellent tool
for studying a wide array of physics effects, including modifications of parton
distribution functions in nuclei, gluon saturation, and color neutralization
and hadronization in a nuclear environment, among others. All of these effects
are expected to have a significant dependence on the size of the nuclear target
and the impact parameter of the collision, also known as the collision
centrality. In this article, we detail a method for determining centrality
classes in p(d)+A collisions via cuts on the multiplicity at backward rapidity
(i.e., the nucleus-going direction) and for determining systematic
uncertainties in this procedure. For d+Au collisions at sqrt(s_NN) = 200 GeV we
find that the connection to geometry is confirmed by measuring the fraction of
events in which a neutron from the deuteron does not interact with the nucleus.
As an application, we consider the nuclear modification factors R_{p(d)+A}, for
which there is a potential bias in the measured centrality dependent yields due
to auto-correlations between the process of interest and the backward rapidity
multiplicity. We determine the bias correction factor within this framework.
This method is further tested using the HIJING Monte Carlo generator. We find
that for d+Au collisions at sqrt(s_NN)=200 GeV, these bias corrections are
small and vary by less than 5% (10%) up to p_T = 10 (20) GeV. In contrast, for
p+Pb collisions at sqrt(s_NN) = 5.02 TeV we find these bias factors are an
order of magnitude larger and strongly p_T dependent, likely due to the larger
effect of multi-parton interactions.Comment: 375 authors, 18 pages, 16 figures, 4 tables. Submitted to Phys. Rev.
C. Plain text data tables for the points plotted in figures for this and
previous PHENIX publications are (or will be) publicly available at
http://www.phenix.bnl.gov/papers.htm
Physiological Signals based Day-Dependence Analysis with Metric Multidimensional Scaling for Sentiment Classification in Wearable Sensors
Azimuthal anisotropy of pi^0 and eta mesons in Au+Au collisions at sqrt(s_NN)=200 GeV
The azimuthal anisotropy coefficients v_2 and v_4 of pi^0 and eta mesons are
measured in Au+Au collisions at sqrt(s_NN)=200 GeV, as a function of transverse
momentum p_T (1-14 GeV/c) and centrality. The extracted v_2 coefficients are
found to be consistent between the two meson species over the measured p_T
range. The ratio of v_4/v_2^2 for pi^0 mesons is found to be independent of p_T
for 1-9 GeV/c, implying a lack of sensitivity of the ratio to the change of
underlying physics with p_T. Furthermore, the ratio of v_4/v_2^2 is
systematically larger in central collisions, which may reflect the combined
effects of fluctuations in the initial collision geometry and finite viscosity
in the evolving medium.Comment: 384 authors, 71 institutions, 11 pages, 9 figures, and 2 tables.
Submitted to Physical Review C. Plain text data tables for the points plotted
in figures for this and previous PHENIX publications are (or will be)
publicly available at http://www.phenix.bnl.gov/papers.htm
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