1,684 research outputs found
The analysis of the charmonium-like states ,, , and according to its strong decay behaviors
Inspired by the newly observed state , we analyze the strong
decay behaviors of some charmonium-like states ,,
, and by the model. We carry out our
work based on the hypothesis that these states are all being the charmonium
systems. Our analysis indicates that charmonium state can be a good
candidate for and state is the possible assignment for
. Considering as the state, the decay behavior of
is inconsistent with the experimental data. So, we can not assign
as the charmonium state by present work. Besides, our
analysis imply that it is reasonable to assign and to be
the same state, . However, combining our analysis with that of
Zhou~\cite{ZhouZY}, we speculate that / might not be a pure
systems
Analysis of the strong coupling form factors of and in QCD sum rules
In this article, we study the strong interaction of the vertexes
and using the three-point QCD sum rules under two different dirac
structures. Considering the contributions of the vacuum condensates up to
dimension in the operation product expansion, the form factors of these
vertexes are calculated. Then, we fit the form factors into analytical
functions and extrapolate them into time-like regions, which giving the
coupling constant. Our analysis indicates that the coupling constant for these
two vertexes are and
.Comment: 6 figure
Strong coupling constants and radiative decays of the heavy tensor mesons
In this article, we analyze tensor-vector-pseudoscalar(TVP) type of vertices
, , ,
, , ,
, , and
, in the frame work of three point QCD sum rules.
According to these analysis, we calculate their strong form factors which are
used to fit into analytical functions of . Then, we obtain the strong
coupling constants by extrapolating these strong form factors into deep
time-like regions. As an application of this work, the coupling constants for
radiative decays of these heavy tensor mesons are also calculated at the point
of . With these coupling constants, we finally calculate the radiative
decay widths of these tensor mesons.Comment: arXiv admin note: text overlap with arXiv:1810.0597
Analysis of the charmed mesons , and
In this work, we systematically study the strong decay behaviors of the
charmed mesons , and
reported by the LHCb collaboration. By comparing the masses and the decay
properties with the results of the experiment, we assigned these newly observed
mesons as the , and
states respectively. As a byproduct, we also study the
strong decays of the unobserved and
charmed mesons, which is helpful to the future experiments in searching for
these charmed mesons.Comment: arXiv admin note: text overlap with arXiv:0803.0106 by other author
Systematic analysis of the , , , , and in meson family
In this work, we tentatively assign the charmed mesons ,
, , , and
observed by the LHCb collaboration according to their
spin-parity and masses, then study their strong decays to the ground state
charmed mesons plus light pseudoscalar mesons with the model.
According to these study, we assigned the as the
state, the as the
or state, the as the or
state in the meson family. As a byproduct, we also
study the strong decays of ,,
, etc, states, which will be helpful
to further experimentally study mixings of these mesons.Comment: 16 pages,1 figure. arXiv admin note: text overlap with
arXiv:0801.4821 by other author
Analysis of the strong vertices of and in QCD sum rules
The strong coupling constant is an important parameter which can help us to
understand the strong decay behaviors of baryons. In our previous work, we have
analyzed strong vertices , ,
, in QCD sum rules. Following these work, we
further analyze the strong vertices and
using the three-point QCD sum rules under Dirac structures
and . In this
work, we first calculate strong form factors considering contributions of the
perturbative part and the condensate terms ,
and . Then, these form factors are used to fit into analytical functions.
According to these functions, we finally determine the values of the strong
coupling constants for these two vertices and
.Comment: arXiv admin note: text overlap with arXiv:1705.0322
Comparative study of earthquake-related and non-earthquake-related head traumas using multidetector computed tomography
OBJECTIVE: The features of earthquake-related head injuries may be different from those of injuries obtained in daily life because of differences in circumstances. We aim to compare the features of head traumas caused by the Sichuan earthquake with those of other common head traumas using multidetector computed tomography. METHODS: In total, 221 patients with earthquake-related head traumas (the earthquake group) and 221 patients with other common head traumas (the non-earthquake group) were enrolled in our study, and their computed tomographic findings were compared. We focused the differences between fractures and intracranial injuries and the relationships between extracranial and intracranial injuries. RESULTS: More earthquake-related cases had only extracranial soft tissue injuries (50.7% vs. 26.2%, RR=1.9), and fewer cases had intracranial injuries (17.2% vs. 50.7%, RR = 0.3) compared with the non-earthquake group. For patients with fractures and intracranial injuries, there were fewer cases with craniocerebral injuries in the earthquake group (60.6% vs. 77.9%, RR = 0.8), and the earthquake-injured patients had fewer fractures and intracranial injuries overall (1.5 + 0.9 vs. 2.5 +1.8; 1.3 + 0.5 vs. 2.1 + 1.1). Compared with the non-earthquake group, the incidences of soft tissue injuries and cranial fractures combined with intracranial injuries in the earthquake group were significantly lower (9.8% vs. 43.7%, RR = 0.2; 35.1% vs. 82.2%, RR = 0.4). CONCLUSION: As depicted with computed tomography, the severity of earthquake-related head traumas in survivors was milder, and isolated extracranial injuries were more common in earthquake-related head traumas than in non-earthquake-related injuries, which may have been the result of different injury causes, mechanisms and settings
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