917 research outputs found
Exclusive Baryonic B Decays Circa 2005
The status of exclusive two-body and three-body baryonic B decays is
reviewed. The threshold enhancement effect in the dibaryon invariant mass and
the angular distributions in the dibaryon rest frame are stressed and
explained. Weak radiative baryonic B decays mediated by the electromagnetic
penguin process are discussed. Puzzles with the correlation
observed in decay and the unexpectedly large rate observed
for are examined. The former may indicate that
the system is produced through some intermediate states, while the
latter implies the failure of naive factorization for
modes and may hint at the importance of final-state rescattering effects.Comment: 21 pages, 9 figures, talk presented at 3rd International Conference
on Flavor Physics, Oct 3-8, 2005, National Central Univ. Chung-li, Taiwa
Pseudovector components of the pion, pi^0 -> gamma gamma, and F_pi(q^2)
As a consequence of dynamical chiral symmetry breaking the pion
Bethe-Salpeter amplitude necessarily contains terms proportional to gamma_5
gamma.P and gamma_5 gamma.k, where k is the relative and P the total momentum
of the constituents. These terms are essential for the preservation of low
energy theorems, such as the Gell-Mann--Oakes-Renner relation and those
describing anomalous decays of the pion, and to obtaining an electromagnetic
pion form factor that falls as 1/q^2 for large q^2, up to calculable
ln(q^2)-corrections. In a simple model, which correlates low- and high-energy
pion observables, we find q^2 F_pi(q^2) ~ 0.12 - 0.19 GeV^2 for q^2 >~10 GeV^2.Comment: 15 pages, 2 figures, REVTE
SNAP satellite focal plane development
The proposed SuperNova/Acceleration Probe (SNAP) mission will have a two-meter class telescope delivering diffraction-limited images to an instrumented 0.7 square degree field in the visible and near-infrared wavelength regime. The requirements for the instrument suite and the present configuration of the focal plane concept are presented. A two year R&D phase, largely supported by the Department of Energy, is just beginning. We describe the development activities that are taking place to advance our preparedness for mission proposal in the areas of detectors and electronics
Pion Form Factor in the NLC QCD SR approach
We present results of a calculation of the electromagnetic pion form factor
within a framework of QCD Sum Rules with nonlocal condensates and using a
perturbative spectral density which includes \mathcal{O}(\alpha_s)
contributions.Comment: 9 pages, 2 figures (embedded). Talk presented by the second author at
the Workshop on Physics of Fundamental Interactions, Institute of High Energy
Physics, Protvino, Russia, 22--25 December 200
Active cooling control of the CLEO detector using a hydrocarbon coolant farm
We describe a novel approach to particle-detector cooling in which a modular
farm of active coolant-control platforms provides independent and regulated
heat removal from four recently upgraded subsystems of the CLEO detector: the
ring-imaging Cherenkov detector, the drift chamber, the silicon vertex
detector, and the beryllium beam pipe. We report on several aspects of the
system: the suitability of using the aliphatic-hydrocarbon solvent PF(TM)-200IG
as a heat-transfer fluid, the sensor elements and the mechanical design of the
farm platforms, a control system that is founded upon a commercial programmable
logic controller employed in industrial process-control applications, and a
diagnostic system based on virtual instrumentation. We summarize the system's
performance and point out the potential application of the design to future
high-energy physics apparatus.Comment: 21 pages, LaTeX, 5 PostScript figures; version accepted for
publication in Nuclear Instruments and Methods in Physics Research
Does fix the Electromagnetic Form Factor at ?
We show that the decay is a reliable
source of information for the electromagnetic form factor of the pion at
by using general arguments to estimate, or
rather, put upper bounds on, the background processes that could spoil this
extraction. We briefly comment on the significance of the resulting
.Comment: 10 pages revtex manuscript, one figure--not included, U. of MD PP
#94-00
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Brokering intercultural relations in the rainbow nation: introducing intercultural marketing
This paper considers the role of marketing in building intercultural relations in superdiverse, post-colonial societies, using post-apartheid South Africa as a case study. Drawing on neo-institutional theory, we analyze South African advertising campaigns to determine how marketing brokers intercultural relations by legitimizing social meanings conveyed through nation-building ideologies and consumers’ lived experiences. We examine whether marketing outputs align with stages of Rainbow Nation-building strategies and types of consumers’ lived experiences of South Africa’s superdiversity. We then derive a conceptualization of intercultural marketing, which we characterize as an approach focused on brokering meanings of convivial intercultural engagement and collective development of societal welfare goals. We contribute to macromarketing theory, directing attention to the important brokering role marketing has, in bridging conceptions of reconciliatory social development held by public policy makers and by societies’ populations. By conceptualizing intercultural marketing, its goals and tools, we contribute to multiculturally-sensitive marketing research and practice advancement
New Constraints on Dispersive Form Factor Parameterizations from the Timelike Region
We generalize a recent model-independent form factor parameterization derived
from rigorous dispersion relations to include constraints from data in the
timelike region. These constraints dictate the convergence properties of the
parameterization and appear as sum rules on the parameters. We further develop
a new parameterization that takes into account finiteness and asymptotic
conditions on the form factor, and use it to fit to the elastic \pi
electromagnetic form factor. We find that the existing world sample of timelike
data gives only loose bounds on the form factor in the spacelike region, but
explain how the acquisition of additional timelike data or fits to other form
factors are expected to give much better results. The same parameterization is
seen to fit spacelike data extremely well.Comment: 24 pages, latex (revtex), 3 eps figure
Branching Ratio and CP Violation of B to pi pi Decays in Perturbative QCD Approach
We calculate the branching ratios and CP asymmetries for B^0 to pi^+pi^-, B^+
to pi^+pi^0 and B^0 to pi^0pi^0 decays, in a perturbative QCD approach. In this
approach, we calculate non-factorizable and annihilation type contributions, in
addition to the usual factorizable contributions. We found that the
annihilation diagram contributions are not very small as previous argument. Our
result is in agreement with the measured branching ratio of B to pi^+pi^- by
CLEO collaboration. With a non-negligible contribution from annihilation
diagrams and a large strong phase, we predict a large direct CP asymmetry in
B^0 to pi^+pi^-, and pi^0pi^0, which can be tested by the current running B
factories.Comment: Latex, 28 pages including 11 figures; added contents and figures,
corrected typo
Person localization using sensor information fusion
Nowadays the incredible grow of mobile devices market led
to the need for location-aware applications. However, sometimes person
location is di cult to obtain, since most of these devices only have a GPS
(Global Positioning System) chip to retrieve location. In order to sup-
press this limitation and to provide location everywhere (even where a
structured environment doesn't exist) a wearable inertial navigation sys-
tem is proposed, which is a convenient way to track people in situations
where other localization systems fail. The system combines pedestrian
dead reckoning with GPS, using widely available, low-cost and low-power
hardware components. The system innovation is the information fusion
and the use of probabilistic methods to learn persons gait behavior to
correct, in real-time, the drift errors given by the sensors.This work is part-funded by ERDF - European Regional Development Fund through
the COMPETE Programme (operational programme for competitiveness) and by
National Funds through the FCT Fundao para a Cincia e a Tecnologia (Portuguese
Foundation for Science and Technology) within project FCOMP-01-0124-FEDER-
028980 (PTDC/EEI-SII/1386/2012). Ricardo also acknowledge FCT for the support
of his work through the PhD grant (SFRH/DB/70248/2010)
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