aCORN: Measuring the electron-antineutrino correlation in neutron beta decay

The aCORN experiment uses a novel asymmetry method to measure the electron-antineutrino correlation (a-coefficient) in free neutron decay that does not require precision proton spectroscopy. aCORN completed two physics runs at the NIST Center for Neutron Research. The first run on the NG-6 beam line obtained the result a = 0.1090 +/- 0.0030 (stat) +/- 0.0028 (sys), the most precise to date. The second run on the new NG-C high flux beam line promises an improvement in precision to ¡ 2%. In addition we show that an improved measurement of the neutrino asymmetry (B-coefficient) can be made using the aCORN apparatus on a highly polarized neutron beam

aCORN: Measuring the electron-antineutrino correlation in neutron beta decay

The aCORN experiment uses a novel asymmetry method to measure the electron-antineutrino correlation (a-coefficient) in free neutron decay that does not require precision proton spectroscopy. aCORN completed two physics runs at the NIST Center for Neutron Research. The first run on the NG-6 beam line obtained the result a = 0.1090 +/- 0.0030 (stat) +/- 0.0028 (sys), the most precise to date. The second run on the new NG-C high flux beam line promises an improvement in precision to ¡ 2%. In addition we show that an improved measurement of the neutrino asymmetry (B-coefficient) can be made using the aCORN apparatus on a highly polarized neutron beam

Genetic typing of classical swine fever viruses from Lao PDR by analysis of the 5' non-coding region

The 5′ non-coding region (5′-NCR) of 27 classical swine fever virus (CSFV) isolates from Lao People's Democratic Republic (Lao PDR) during 1997 and 1999 were amplified by RT-PCR. A 150-bp region of the 5′-NCR amplicons was analysed and compared with reference CSFV of European and Asian origin and a phylogenetic dendrogram constructed. Following analysis, all viruses were determined to belong to genogroup 2. Viruses from Lao PDR grouped on a geographical basis with the majority of northern/central isolates falling into subgroup 2.1 and southern/central isolates falling into subgroup 2.2. These results concur with previous studies of CSF viruses from Lao PDR, although this study recognized the first occurrence of subgroup 2.1 in southern Lao PDR