49 research outputs found
Complementary Currencies for Sustainable Development in Kenya
This paper is a report on the development of a complementary currency system that allows Kenyans in informal settlements to trade goods and services and meet sustainable development objectives. The system in this report, Bangla-Pesa, uses a ‘collaborative credit’ model through a network of local business, whose owners often struggle to meet their basic needs (also known as ‘mutual credit’). The paper documents the reasons for its creation, how it was launched, the immediate positive benefits upon launch, and some of the difficulties faced. Bangla-Pesa is shown to have facilitated, upon its launch, exchanges of roughly 50 Euros in value per day among 109 businesses, which is projected to raise living standards in the community primarily through the utilization of excess business capacity. After only a week of circulation – Bangla-Pesa represented an estimated 22 total trade among community members. This system’s implementation and governance model are detailed with the aim of improving upon and replicating the model for future sustainable development programs
EuFeAs under high pressure: an antiferromagnetic bulk superconductor
We report the ac magnetic susceptibility and resistivity
measurements of EuFeAs under high pressure . By observing nearly
100% superconducting shielding and zero resistivity at = 28 kbar, we
establish that -induced superconductivity occurs at ~30 K in
EuFeAs. shows an anomalous nearly linear temperature dependence
from room temperature down to at the same . indicates that
an antiferromagnetic order of Eu moments with ~20 K persists
in the superconducting phase. The temperature dependence of the upper critical
field is also determined.Comment: To appear in J. Phys. Soc. Jpn., Vol. 78 No.
The BaBar detector: Upgrades, operation and performance
Contains fulltext :
121729.pdf (preprint version ) (Open Access
The e(+)e(-)-> 2(pi(+)pi(-))pi(0), 2(pi(+)pi(-))eta, K+K-pi(+)pi(-)pi(0) and K+K-pi(+)pi(-)eta cross sections measured with initial-state radiation
We study the processes e(+)e(-)-> 2(pi(+)pi(-))pi(0)gamma, 2(pi(+)pi(-))eta gamma, K+K-pi(+)pi(-)pi(0)gamma and K+K-pi(+)pi(-)eta gamma with the hard photon radiated from the initial state. About 20 000, 4300, 5500, and 375 fully reconstructed events, respectively, are selected from 232 fb(-1) of BABAR data. The invariant mass of the hadronic final state defines the effective e(+)e(-) center-of-mass energy, so that the obtained cross sections from the threshold to about 5 GeV can be compared with corresponding direct e(+)e(-) measurements, currently available only for the eta pi(+)pi(-) and omega pi(+)pi(-) submodes of the e(+)e(-)-> 2(pi(+)pi(-))pi(0) channel. Studying the structure of these events, we find contributions from a number of intermediate states, and we extract their cross sections where possible. In particular, we isolate the contribution from e(+)e(-)->omega(782)pi(+)pi(-) and study the omega(1420) and omega(1650) resonances. In the charmonium region, we observe the J/psi in all these final states and several intermediate states, as well as the psi(2S) in some modes, and we measure the corresponding branching fractions
Amplitude analysis of the decay D0→K-K+π0
Using 385 fb(-1) of e(+)e(-) collisions, we study the amplitudes of the singly Cabibbo-suppressed decay D-0 -> K-K+pi(0). We measure the strong phase difference between the (D) over bar (0) and D-0 decays to K-*(892)K-+(-) to be -35.5 degrees +/- 1.9 degrees(stat)+/- 2.2 degrees(syst), and their amplitude ratio to be 0.599 +/- 0.013(stat)+/- 0.011(syst). We observe contributions from the K pi and K-K+ scalar and vector amplitudes, and analyze their angular moments. We find no evidence for charged kappa, nor for higher spin states. We also perform a partial-wave analysis of the K-K+ system in a limited mass range
Observation of Decays and
7 pages, 2 postscript figues, submitted to Physical Review Letters - P. Grenier aussi au LPCWe report the observation of decays B0->D_s(*)+pi- and B0->D_s(*)-K+ in a sample of 230*10^6 Upsilon(4S)->BBbar events recorded with the BaBar detector at the PEP-II asymmetric-energy e+e- storage ring. We measure the branching fractions B(B0->D_s+pi-)=(1.3 +/- 0.3 (stat.) +/- 0.2 (syst.))*10^{-5}, B(B0->D_s-K+)=(2.5 +/- 0.4 (stat.) +/- 0.4 (syst.))*10^{-5}, B(B0->D_s*+pi-)=(2.8 +/- 0.6 (stat.) +/- 0.5 (syst.))*10^{-5}, and B(B0->D_s*-K+)=(2.0 +/- 0.5 (stat.) +/- 0.4 (syst.))*10^{-5}. The significance of the measurements to differ from zero are 5, 9, 6, and 5 standard deviations, respectively
Improved measurement of CP violation in neutral B decays to ccs
We present updated measurements of time-dependent CP asymmetries in fully-reconstructed neutral B decays to several CP eigenstates containing a charmonium meson. The measurements use a data sample of (383 +/- 4) x 10(6) Y (4S) -> B (B) over bar decays collected with the BABAR detector at the PEP-II B factory. We determine sin2 beta = 0.714 +/- 0.032(stat) +/- 0.018(syst) and |lambda| = 0.952 +/- 0.022(stat) +/- 0.017(syst)
Observation of B meson decays to b(1)pi and b(1)K
We present the results of searches for decays of B mesons to final states with a b(1) meson and a charged pion or kaon. The data, collected with the BABAR detector at the Stanford Linear Accelerator Center, represent 382x10(6) B(B)over bar pairs produced in e(+)e(-) annihilation. The results for the branching fractions are, in units of 10(-6), B(B+ -> b(1)(0)pi(+)) = 6.7 +/- 1.7 +/- 1.0, B(B+ -> b(1)(0)K(+)) = 9.1 +/- 1.7 +/- 1.0, B(B-0 -> b(1)(-/+)pi +/- ) = 10.9 +/- 1.2 +/- 0.9, and B(B-0 -> b(1)(-)K(+)) = 7.4 +/- 1.0 +/- 1.0, with the assumption that B(b(1) -> omega pi) = 1. We also measure charge and flavor asymmetries A(ch)(B+ -> b(1)(0)pi(+)) = 0.05 +/- 0.16 +/- 0.02, A(ch)(B+ -> b(1)(0)K(+)) = -0.46 +/- 0.20 +/- 0.02, A(ch)(B-0 -> b(1)(-/+)pi +/- ) = -0.05 +/- 0.10 +/- 0.02, C(B-0 -> b(1)(-/+)pi +/- ) = -0.22 +/- 0.23 +/- 0.05, Delta C(B-0 -> b(1)(-/+)pi +/- ) = -1.04 +/- 0.23 +/- 0.08, and A(ch)(B-0 -> b(1)(-)K(+)) = -0.07 +/- 0.12 +/- 0.02. The first error quoted is statistical, and the second systematic
Measurements of CP-Violating Asymmetries in the Decay B^{0}→K^{+}K^{-}K^{0}
We analyze the decay B0→K+K-K0 using 383×106 BB̅ events collected by the BABAR detector at SLAC to extract CP violation parameter values over the Dalitz plot. Combining all K+K-K0 events, we find ACP=-0.015±0.077±0.053 and βeff=0.352±0.076±0.026 rad, corresponding to a CP violation significance of 4.8σ. A second solution near π/2-βeff is disfavored with a significance of 4.5σ. We also report ACP and βeff separately for decays to ϕ(1020)K0, f0(980)K0, and K+K-K0 with mK+K->1.1 GeV/c2