5,016 research outputs found
Properties of the scalar mesons , and
In the three-state mixing framework, considering the possible glueball
components of and , we investigate the hadronic decays of
, and into two pseudoscalar mesons. The
quarkonia-glueball content of the three states is determined from the fit to
the new data presented by the WA102 Collaboration. We find that these data are
insensitive to the possible glueball components of and .
Furthermore, we discuss some properties of the mass matrix describing the
mixing of the isoscalar scalar mesons.Comment: Latex 14 pages including 1 eps figur
Nonadiabatic dynamics and geometric phase of an ultrafast rotating electron spin
The spin in a rotating frame has attracted a lot of attentions recently, as
it deeply relates to both fundamental physics such as pseudo-magnetic field and
geometric phase, and applications such as gyroscopic sensors. However, previous
studies only focused on adiabatic limit, where the rotating frequency is much
smaller than the spin frequency. Here we propose to use a levitated
nano-diamond with a built-in nitrogen-vacancy (NV) center to study the dynamics
and the geometric phase of a rotating electron spin without adiabatic
approximation. We find that the transition between the spin levels appears when
the rotating frequency is comparable to the spin frequency at zero magnetic
field. Then we use Floquet theory to numerically solve the spin energy
spectrum, study the spin dynamics and calculate the geometric phase under a
finite magnetic field, where the rotating frequency to fulfill the resonant
transition condition could be greatly reduced.Comment: 6+2 pages, 3+1 figure
A proposal on the search for the hybrid with in the process at upgraded BEPC/BES
The moment expressions for the boson resonances X with spin-parity 0++, 1-+,
1++, and 2++ possibly produced in the process , , are given in terms of the generalized moment
analysis method. The 1-+ resonance can be distinguished from other resonances
by means of these moments except for some rather special cases. The suggestion
that the search for the 1-+ hybrid can be performed in the above decay channel
at upgraded BEPC/BES is presented.Comment: Latex 13 pages, no figur
Excited Heavy Quarkonium Production at the LHC through -Boson Decays
Sizable amount of heavy-quarkonium events can be produced through -boson
decays at the LHC. Such channels will provide a suitable platform to study the
heavy-quarkonium properties. The "improved trace technology", which disposes
the amplitude at the amplitude-level, is helpful for deriving
compact analytical results for complex processes. As an important new
application, in addition to the production of the lower-level Fock states
and , we make a further study on the
production of higher-excited -quarkonium Fock states
, and . Here
stands for the -charmonium,
-quarkonium and -bottomonium respectively. We show
that sizable amount of events for those higher-excited states can also be
produced at the LHC. Therefore, we need to take them into consideration for a
sound estimation.Comment: 7 pages, 9 figures and 6 tables. Typo errors are corrected, more
discussions and two new figures have been adde
Doubly Heavy Baryon Production at A High Luminosity Collider
Within the framework of nonrelativistic QCD, we make a detailed discussion on
the doubly heavy baryon production through the annihilation channel,
, at a high luminosity collider. Here
stands for the heavy or quark. In addition to the
channel through the usually considered diquark state
, contributions from the channels through
other same important diquark states such as have
also been discussed. Uncertainties for the total cross sections are predicted
by taking GeV and GeV. At a super
-factory running around the mass and with a high luminosity up to
, we estimate
that about events,
events and events can be
generated in one operation year. Such a -factory, thus, will provide a good
platform for studying the doubly heavy baryons in comparable to the CERN large
hadronic collider.Comment: 9 pages, 4 figures. To be published in Phys.Rev.
PS: Precise Patch Presence Test based on Semantic Symbolic Signature
During software development, vulnerabilities have posed a significant threat
to users. Patches are the most effective way to combat vulnerabilities. In a
large-scale software system, testing the presence of a security patch in every
affected binary is crucial to ensure system security. Identifying whether a
binary has been patched for a known vulnerability is challenging, as there may
only be small differences between patched and vulnerable versions. Existing
approaches mainly focus on detecting patches that are compiled in the same
compiler options. However, it is common for developers to compile programs with
very different compiler options in different situations, which causes
inaccuracy for existing methods. In this paper, we propose a new approach named
PS3, referring to precise patch presence test based on semantic-level symbolic
signature. PS3 exploits symbolic emulation to extract signatures that are
stable under different compiler options. Then PS3 can precisely test the
presence of the patch by comparing the signatures between the reference and the
target at semantic level.
To evaluate the effectiveness of our approach, we constructed a dataset
consisting of 3,631 (CVE, binary) pairs of 62 recent CVEs in four C/C++
projects. The experimental results show that PS3 achieves scores of 0.82, 0.97,
and 0.89 in terms of precision, recall, and F1 score, respectively. PS3
outperforms the state-of-the-art baselines by improving 33% in terms of F1
score and remains stable in different compiler options.Comment: Accepted to ICSE 2024; Camera-ready versio
Study on Unloading-wet Swelling Mechanism of Upper Arch Deformation of Mudstone Subgrade in a High-speed Railway
Mudstone subgrade may exhibit rather complicated deformation behavior under the coupling effect of unloading and wet swelling caused by subgrade excavation. To study the deformation mechanism of mudstone subgrade, mudstones were sampled from the NO.3 branch tunnel of Badong section of Zhengzhou-Wanzhou High-speed Railway and a series of unloading and wet-swelling tests were carried out on them. We studied the long-term deformation behavior of mudstone subgrade caused by excavation based on a creep test with unloading conditions. The expansion rate of the complete mudstone cylinder samples was extremely low under the wetting and drying cycle, while that of the soil samples after the disintegration of complete mudstone was between 1% and 10% when immersed in water. Excavation unloading damage, groundwater infiltration, long-term creep deformation, dry-wet cycle, and hot-cold alternation catalyzed each other, leading to the aggravation of mudstone disintegration and the obvious increase of expansibility of underwater mudstone after disintegration. The maximum arch deformation of mudstone subgrade can be divided into three parts: the rebound deformation during short-term excavation, the creep deformation related to time and the wet-swelling deformation. Generally, the creep deformation would not converge in two years if support measures were not taken, the wet-swelling deformation could tend to a steady value after a certain period of excavation
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