5,007 research outputs found
Testing Fundamental Symmetries with \Lambda_b \to \Lambda -Vector Decay
Putting together kinematical and dynamical analysis, a complete study of the
decay channels , with
and or
is performed. An intensive use of the helicity formalism is involved on the
kinematical side, while on the dynamical side, Heavy Quark Effective Theory
(HQET) is applied for an accurate determination of the hadronic matrix elements
between the baryons and . Emphasis is put on the major
role of the polarization for constructing T-odd observables and the
standard mixing has the benefit effect of amplifying the
process of direct CP violation between decays.Comment: 47 pages, 10 figures and 3 table
Better Indoor Climate With Less Energy: European Energy Performance of Building Directive (EPBD)
The European Commission's Action Plan on Energy Efficiency (2000) indicated the need for specific measures in the building sector. In response, the European Commission (EC) published the proposed Directive on the Energy Performance of Buildings (EPBD) in May 2001. The European Parliament and Council accepted the text, and it was published in the EU Official Journal in January 2003, at which time the Directive became a European Law. The objective of the EPBD is to promote the improvement of the energy performance of buildings, taking into account outdoor climatic and local conditions, as well as indoor climate requirements. The main objective is to achieve better indoor climate with less energy
Radioactive ion beam development in Berkeley
Two radioactive ion beam projects are under development at the 88" Cyclotron, BEARS (Berkeley Experiment with accelerated radioactive species) and the 14O experiment. The projects are initially focused on the production of 11C and 14O, but it is planned to expand the program to 17F, 18F, 13N and 76Kr. For the BEARS project, the radioactivity is produced in form of either CO2 or N2O in a small medical 10 MeV proton cyclotron. The activity is then transported through a 300 m long He-jet line to the 88" cyclotron building, injected into the AECR-U ion source and accelerated through the 88" cyclotron to energies between 1 to 30 MeV/ nucleon. The 14O experiment is a new experiment at the 88" cyclotron to measure the energy-shape of the beta decay spectrum. For this purpose, a target transfer line and a radioactive ion beam test stand has been constructed. The radioactivity is produced in form of CO in a hot carbon target with a 20 MeV 3He from the 88" Cyclotron. The activity diffuses through an 8m long stainless steel line into the 6 GHz ECR ion source IRIS (Ion source for Radioactive ISotopes). It is then ionized and accelerated to 30 keV to mass separate the 14O and then implanted into a carbon foil. In order to optimize the on-line efficiencies of the LBNL ECR ion sources, off-line ionization efficiency studies are carried out for various gases. A summary of the ionization efficiency measurements is presented
Direct CP Violation in B decays with rho0-omega Mixing
A complete study of the process B to pi+ pi- V(V=1--) is performed both in
the framework of the helicity formalism and the effective lagrangian approach.
Emphasis is put on the factorization hypothesis and the importance of the rho0-
omega mixing in enhancing the direct CP violation. New results involving some
branching ratios and the ratio of the Penguin/Tree amplitude are given in
details.Comment: 7 pages, 2 figures. Talk oresented by ZJA at the 18th International
Workshop on High energy Physics and Quantum Field Theory, QFTHEP004,
St-Petersbug, RUSSIA, JUne 17-23, 200
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Design Study of the Extraction System of the 3rd Generation ECR Ion Source
A design study for the extraction system of the 3rd Generation super conducting ECR ion source at LBNL is presented. The magnetic design of the ion source has a mirror field of 4 T at the injection and 3 T at the extraction side and a radial field of 2.4 T at the plasma chamber wall. Therefore, the ion beam formation takes place in a strong axial magnetic field. Furthermore the axial field drops from 3 T to 0.4 T within the first 30 cm. The influence of the high magnetic field on the ion beam extraction and matching to the beam line is investigated. The extraction system is first simulated with the 2D ion trajectory code IGUN with an estimated mean charge state of the extracted ion beam. These results are then compared with the 2D code AXCEL-INP, which can simulate the extraction of ions with different charge states. Finally, the influence of the strong magnetic hexapole field is studied with the three dimensional ion optics code KOBRA. The introduced tool set can be used to optimize the extraction system of the super conducting ECR ion source
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Overview of the results of the organics PET Study of the cometary samples returned from comet Wild 2 by the Stardust mission
This presenation will provide an overview of the efforts and results produced by the Organics Preliminary Examination Team during their studies of the samples returned from comet Wild 2 by the Stardust spacecraft
New measurement of via neutron capture on hydrogen at Daya Bay
This article reports an improved independent measurement of neutrino mixing
angle at the Daya Bay Reactor Neutrino Experiment. Electron
antineutrinos were identified by inverse -decays with the emitted
neutron captured by hydrogen, yielding a data-set with principally distinct
uncertainties from that with neutrons captured by gadolinium. With the final
two of eight antineutrino detectors installed, this study used 621 days of data
including the previously reported 217-day data set with six detectors. The
dominant statistical uncertainty was reduced by 49%. Intensive studies of the
cosmogenic muon-induced Li and fast neutron backgrounds and the
neutron-capture energy selection efficiency, resulted in a reduction of the
systematic uncertainty by 26%. The deficit in the detected number of
antineutrinos at the far detectors relative to the expected number based on the
near detectors yielded in the
three-neutrino-oscillation framework. The combination of this result with the
gadolinium-capture result is also reported.Comment: 26 pages, 23 figure
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