212 research outputs found
Few-Body Systems Composed of Heavy Quarks
Within the past ten years many new hadrons states were observed
experimentally, some of which do not fit into the conventional quark model. I
will talk about the few-body systems composed of heavy quarks, including the
charmonium-like states and some loosely bound states.Comment: Plenary talk at the 20th International IUPAP Conference on Few-Body
Problems in Physics, to appear in Few Body Systems (2013
Tracing uncertainty contributors in the multi‐hazard risk analysis for compound extremes
In this study, an iterative factorial multimodel Bayesian copula (IFMBC) framework was developed for revealing uncertainties in risk inferences of compound extremes under the consideration of diverse model structures and parameter sets. Particularly, an iterative factorial analysis (IFA) method would be advanced in IFMBC to track the dominant contributors to the imprecise predictions of multi-hazard risks. The developed IFMBC framework was applied for the risk assessment of compound floods at two estuarine systems (i.e., Washington and Philadelphia) in US. The results indicate that the most likely compound events, under predefined return periods, exhibit noticeable uncertainties. Those uncertainties also present multiple hotspots which may be attributed to different impacts from different factors. By applying the IFA method, the results suggest the copula structure would likely be ranked as one of the top 2 impact factors for predictions of failure probabilities (FPs) in the scenarios of AND, and Kendall, with its contributions higher than 30% for FP in Kendall (more than 40% at Washington) and more than 25% for FP in Kendall (larger than 40% at Philadelphia). In comparison, the copula structure may not pose a visible effect on the predictive uncertainty for FP in OR, with its contribution possibly less than 5% under long-term service time periods. However, the marginal distributions would have higher effects on FP in OR than the effects on the other two FPs. Particularly, the marginal distribution for the extreme variable with high skewness and kurtosis values tends to be ranked as one of the most significant impact factors for FP in OR. Also, the overall impacts from parametric uncertainties in both marginal and dependence models cannot be neglected for the predictions of all three failure probabilities (FPs) with their contributions probably larger than 20% under a short service time period. Compared with the traditional multilevel factorial analysis, the IFA method can provide more reliable characterization for uncertainty contributors in multi-hazard risk analyses, since the traditional method seems to significantly overestimate the contributions from parameter uncertainties
OL-085 A candidate genes study for the association of host single nucleotide polymorphisms with liver cirrhosis risk in Chinese hepatitis B patients
Possible Interpretations of If It Really Exists
We analyze various possible interpretations of the narrow state
observed by SELEX Collaboration recently, which lies above
threshold and has abnormal decay pattern. These interpretations include: (1)
several versions of tetraquarks; (2) conventional meson such as the
first radial excitation of with abnormally large SU(3) symmetry
breaking; (3) conventional meson with abnormally large
coupling; (4) heavy hybrid meson. We discuss the physical implications of each
interpretation. For example, if the existence of is confirmed
as the first radial excitation of by other experiments, it will be
helpful to look for (1) its SU(3) flavor partners ; (2) its
B-meson analogues ; (3) S-wave two pion
decay modes
The molecular systems composed of the charmed mesons in the doublet
We study the possible heavy molecular states composed of a pair of charm
mesons in the H and S doublets. Since the P-wave charm-strange mesons
and are extremely narrow, the future experimental
observation of the possible heavy molecular states composed of
and may be feasible if they really exist.
Especially the possible states may be searched for via the
initial state radiation technique.Comment: 42 pages, 4 tables, 31 figures. Improved numerical results and
Corrected typos
Development of an eight-band theory for quantum-dot heterostructures
We derive a nonsymmetrized 8-band effective-mass Hamiltonian for quantum-dot
heterostructures (QDHs) in Burt's envelope-function representation. The 8x8
radial Hamiltonian and the boundary conditions for the Schroedinger equation
are obtained for spherical QDHs. Boundary conditions for symmetrized and
nonsymmetrized radial Hamiltonians are compared with each other and with
connection rules that are commonly used to match the wave functions found from
the bulk kp Hamiltonians of two adjacent materials. Electron and hole energy
spectra in three spherical QDHs: HgS/CdS, InAs/GaAs, and GaAs/AlAs are
calculated as a function of the quantum dot radius within the approximate
symmetrized and exact nonsymmetrized 8x8 models. The parameters of dissymmetry
are shown to influence the energy levels and the wave functions of an electron
and a hole and, consequently, the energies of both intraband and interband
transitions.Comment: 36 pages, 10 figures, E-mail addresses: [email protected],
[email protected]
BESII Detector Simulation
A Monte Carlo program based on Geant3 has been developed for BESII detector
simulation. The organization of the program is outlined, and the digitization
procedure for simulating the response of various sub-detectors is described.
Comparisons with data show that the performance of the program is generally
satisfactory.Comment: 17 pages, 14 figures, uses elsart.cls, to be submitted to NIM
Direct Measurements of the Branching Fractions for and and Determinations of the Form Factors and
The absolute branching fractions for the decays and
are determined using singly
tagged sample from the data collected around 3.773 GeV with the
BES-II detector at the BEPC. In the system recoiling against the singly tagged
meson, events for and events for decays are observed. Those yield
the absolute branching fractions to be and . The
vector form factors are determined to be
and . The ratio of the two form
factors is measured to be .Comment: 6 pages, 5 figure
Study of J/psi decays to Lambda Lambdabar and Sigma0 Sigma0bar
The branching ratios and Angular distributions for J/psi decays to Lambda
Lambdabar and Sigma0 Sigma0bar are measured using BESII 58 million J/psi.Comment: 11 pages, 5 figure
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