570 research outputs found
Quantum algebra in the mixed light pseudoscalar meson states
In this paper, we investigate the entanglement degrees of pseudoscalar meson
states via quantum algebra Y(su(3)). By making use of transition effect of
generators J of Y(su(3)), we construct various transition operators in terms of
J of Y(su(3)), and act them on eta-pion-eta mixing meson state. The
entanglement degrees of both the initial state and final state are calculated
with the help of entropy theory. The diagrams of entanglement degrees are
presented. Our result shows that a state with desired entanglement degree can
be achieved by acting proper chosen transition operator on an initial state.
This sheds new light on the connect among quantum information, particle physics
and Yangian algebra.Comment: 9 pages, 3 figure
Developing a survey to collect expertise in agile product line requirements engineering processes
Current agile methods are focused on practices of small, rapid developing and iteration, more people oriented, less documentation projects, and the use of the methods in large, product line projects are somehow difficult. UTD and GESSI have started a project to develop an expert system that can assist a requirements enginer in selecting a requirements engineering process that is well suited for their project, in particular with respect to the use of agile and product line engineering methods. To the best of our knowledge, this is the first expert system to do this. In this report, we present the questionnaire and the rationale behind it. This report is complemented with LSI-07-14-R.Postprint (published version
Defining project scenarios for the agile requirements engineering product-line development questionnaire
Current agile methods are focused on practices of small, rapid developing and iteration, more people oriented, less documentation projects, and the use of the methods in large, product line projects are somehow difficult. UTD and GESSI have started a project to develop an expert system that can assist a requirements enginer in selecting a requirements engineering process that is well suited for their project, in particular with respect to the use of agile and product line engineering methods. To the best of our knowledge, this is the first expert system to do this. In this report, we present the project scenario requirements, development methodology, and the initial set of 162 project scenarios defined. In the future, version 2 of this report will be released, which will includes additional scenarios. This report is complemented with LSI-07-15-R.Postprint (published version
Evolution and Flare Activity of Delta-Sunspots in Cycle 23
The emergence and magnetic evolution of solar active regions (ARs) of
beta-gamma-delta type, which are known to be highly flare-productive, were
studied with the SOHO/MDI data in Cycle 23. We selected 31 ARs that can be
observed from their birth phase, as unbiased samples for our study. From the
analysis of the magnetic topology (twist and writhe), we obtained the following
results. i) Emerging beta-gamma-delta ARs can be classified into three
topological types as "quasi-beta", "writhed" and "top-to-top". ii) Among them,
the "writhed" and "top-to-top" types tend to show high flare activity. iii) As
the signs of twist and writhe agree with each other in most cases of the
"writhed" type (12 cases out of 13), we propose a magnetic model in which the
emerging flux regions in a beta-gamma-delta AR are not separated but united as
a single structure below the solar surface. iv) Almost all the "writhed"-type
ARs have downward knotted structures in the mid portion of the magnetic flux
tube. This, we believe, is the essential property of beta-gamma-delta ARs. v)
The flare activity of beta-gamma-delta ARs is highly correlated not only with
the sunspot area but also with the magnetic complexity. vi) We suggest that
there is a possible scaling-law between the flare index and the maximum umbral
area
Measurements of the Mass and Full-Width of the Meson
In a sample of 58 million events collected with the BES II detector,
the process J/ is observed in five different decay
channels: , , (with ), (with
) and . From a combined fit of all five
channels, we determine the mass and full-width of to be
MeV/ and
MeV/.Comment: 9 pages, 2 figures and 4 table. Submitted to Phys. Lett.
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
Measurements of J/psi Decays into 2(pi+pi-)eta and 3(pi+pi-)eta
Based on a sample of 5.8X 10^7 J/psi events taken with the BESII detector,
the branching fractions of J/psi--> 2(pi+pi-)eta and J/psi-->3(pi+pi-)eta are
measured for the first time to be (2.26+-0.08+-0.27)X10^{-3} and
(7.24+-0.96+-1.11)X10^{-4}, respectively.Comment: 11 pages, 6 figure
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
Measurement of branching fractions for the inclusive Cabibbo-favored ~K*0(892) and Cabibbo-suppressed K*0(892) decays of neutral and charged D mesons
The branching fractions for the inclusive Cabibbo-favored ~K*0 and
Cabibbo-suppressed K*0 decays of D mesons are measured based on a data sample
of 33 pb-1 collected at and around the center-of-mass energy of 3.773 GeV with
the BES-II detector at the BEPC collider. The branching fractions for the
decays D+(0) -> ~K*0(892)X and D0 -> K*0(892)X are determined to be BF(D0 ->
\~K*0X) = (8.7 +/- 4.0 +/- 1.2)%, BF(D+ -> ~K*0X) = (23.2 +/- 4.5 +/- 3.0)% and
BF(D0 -> K*0X) = (2.8 +/- 1.2 +/- 0.4)%. An upper limit on the branching
fraction at 90% C.L. for the decay D+ -> K*0(892)X is set to be BF(D+ -> K*0X)
< 6.6%
Search for the Lepton Flavor Violation Processes and
The lepton flavor violation processes and are
searched for using a sample of 5.8 events collected with
the BESII detector. Zero and one candidate events, consistent with the
estimated background, are observed in and
decays, respectively. Upper limits on the branching ratios are determined to be
and at the 90% confidence level (C.L.).Comment: 9 pages, 2 figure
- …