13,379 research outputs found
The observed by the BES Collaboration
In the framework of the meson decay model, the strong decays of the
and states are investigated. It is found that in
the presence of the initial state mass being 2.24 GeV, the total widths of the
and states are about 438 MeV and 125 MeV,
respectively. Also, when the initial state mass varies from 2220 to 2400 MeV,
the total width of the state varies from about 100 to 132
MeV, while the total width of the state varies from about
400 to 594 MeV. A comparison of the predicted widths and the experimental
result of GeV, the width of the
with a mass of GeV recently observed by the
BES Collaboration in the radiative decay , suggests that it would be very difficult to identify the
as the state, and the seams a
good candidate for the state.Comment: 14 pages, 3 figures, typos corrected, Accepted by Physical Review
Analysis of HARP TPC krypton data
This memo describes the procedure which was adopted to equalize the response of the 3972 pads of the HARP TPC, using radioactive 83mKr gas. The results obtained from the study of reconstructed krypton clusters in the calibration data taken in 2002 are reported. Two complementary methods were employed in the data analysis. Compatible results were obtained for channel-to-channel equalization constants. An estimate of the overall systematic uncertainty was derived
The composition and size distribution of the dust in the coma of comet Hale-Bopp
We discuss the composition and size distribution of the dust in the coma of
comet Hale-Bopp. We do this by fitting simultaneously the infrared emission
spectrum measured by the infrared space observatory (ISO) and the measured
degree of linear polarization of scattered light at various phase angles and 12
different wavelengths. The effects of particle shape on the modeled optical
properties of the dust grains are taken into account. We constrain our fit by
forcing the abundances of the major rock forming chemical elements to be solar.
The infrared spectrum at long wavelengths reveals that large grains are needed
in order to fit the spectral slope. The size and shape distribution we employ
allows us to estimate the sizes of the crystalline silicates. The ratios of the
strength of various forsterite features show that the crystalline silicate
grains in Hale-Bopp must be submicron sized. We exclude the presence of large
crystalline silicate grains in the coma. Because of this lack of large
crystalline grains combined with the fact that we do need large amorphous
grains to fit the emission spectrum at long wavelengths, we need only
approximately 4% of crystalline silicates by mass. After correcting for
possible hidden crystalline material included in large amorphous grains, our
best estimate of the total mass fraction of crystalline material is
approximately 7.5%, significantly lower than deduced in previous studies in
which the typical derived crystallinity is 20-30%. The implications of this on
the possible origin and evolution of the comet are discussed. The crystallinity
we observe in Hale-Bopp is consistent with the production of crystalline
silicates in the inner solar system by thermal annealing and subsequent radial
mixing to the comet forming region.Comment: Accepted for publication in Icaru
On the Matrix Element of the Transverse Component of Bilocal Vector Current and its Parton Interpretation
In this paper we study the matrix element of the transverse component of the
bilocal vector current in the context of deep inelastic scattering. BJL limit
of high energy amplitudes together with light-front current algebra imply the
same parton interpretation for its matrix element as that of the plus
component. On the other hand, the transverse component depends explicitly on
the gluon field operator in QCD, appears as "twist three" and hence its matrix
element has no manifest parton interpretation. In this paper we perform
calculations in light-front time-ordering perturbative QCD for a dressed quark
target to order and demonstrate that the matrix element of the
transverse component of the bilocal vector current has the same parton
interpretation as that of the plus component.Comment: 7 pages, REVTE
Search for charginos, neutralinos, and gravitinos at LEP
The hep-ex data base was decided not to be an appropriate place to make
DELPHI notes public. Sorry for the inconvenience.Comment: the paper should not have been made publi
Learning Bodily and Temporal Attention in Protective Movement Behavior Detection
For people with chronic pain, the assessment of protective behavior during
physical functioning is essential to understand their subjective pain-related
experiences (e.g., fear and anxiety toward pain and injury) and how they deal
with such experiences (avoidance or reliance on specific body joints), with the
ultimate goal of guiding intervention. Advances in deep learning (DL) can
enable the development of such intervention. Using the EmoPain MoCap dataset,
we investigate how attention-based DL architectures can be used to improve the
detection of protective behavior by capturing the most informative temporal and
body configurational cues characterizing specific movements and the strategies
used to perform them. We propose an end-to-end deep learning architecture named
BodyAttentionNet (BANet). BANet is designed to learn temporal and bodily parts
that are more informative to the detection of protective behavior. The approach
addresses the variety of ways people execute a movement (including healthy
people) independently of the type of movement analyzed. Through extensive
comparison experiments with other state-of-the-art machine learning techniques
used with motion capture data, we show statistically significant improvements
achieved by using these attention mechanisms. In addition, the BANet
architecture requires a much lower number of parameters than the state of the
art for comparable if not higher performances.Comment: 7 pages, 3 figures, 2 tables, code available, accepted in ACII 201
On the mass relation of a meson nonet
It is pointed out that the omission of the effects of the transition between
quarkonia or the assumption that the transition between quarkonia is
flavor-independent would result in the inconsistent results for the
pseudoscalar meson nonet. It is emphasized that the mass relation of the
non-ideal mixing meson nonets should incorporate the effects of the
flavor-dependent transition between quarkonia. The new mass relations of a
meson nonet are presented.Comment: Latex, 10 pages, to appear in Mod. Phys. Lett.
Evidence for the disintegration of KIC 12557548 b
Context. The Kepler object KIC 12557548 b is peculiar. It exhibits
transit-like features every 15.7 hours that vary in depth between 0.2% and
1.2%. Rappaport et al. (2012) explain the observations in terms of a
disintegrating, rocky planet that has a trailing cloud of dust created and
constantly replenished by thermal surface erosion. The variability of the
transit depth is then a consequence of changes in the cloud optical depth.
Aims. We aim to validate the disintegrating-planet scenario by modeling the
detailed shape of the observed light curve, and thereby constrain the cloud
particle properties to better understand the nature of this intriguing object.
Methods. We analysed the six publicly-available quarters of raw Kepler data,
phase-folded the light curve and fitted it to a model for the trailing dust
cloud. Constraints on the particle properties were investigated with a
light-scattering code. Results. The light curve exhibits clear signatures of
light scattering and absorption by dust, including a brightening in flux just
before ingress correlated with the transit depth and explained by forward
scattering, and an asymmetry in the transit light curve shape, which is easily
reproduced by an exponentially decaying distribution of optically thin dust,
with a typical grain size of 0.1 micron. Conclusions. Our quantitative analysis
supports the hypothesis that the transit signal of KIC 12557548 b is due to a
variable cloud of dust, most likely originating from a disintegrating object.Comment: 5 pages, 4 figures. Accepted for publication in Astronomy and
Astrophysic
Towards the assignment for the meson nonet
The strong decays of the , , ,
, and as the quark-antiquark states are
investigated in the framework of the meson decay model. It is found
that the , , and appear to be the
convincing states while the assignment of the
and as the isoscalar states is not favored by their
widths. In the presence of the , , and
being the members of the meson nonet, the kaon is
phenomenologically determined to has a mass of about 2153 MeV. The width of
this unobserved kaon is expected to be about 197 MeV in the decay
model.Comment: 15 pages, 5 figures, version accepted for publication in Physical
Review
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