Spin rotation schemes at the ILC for two interaction regions and positron polarization with both helicities

This note describes a spin rotation scheme for the ILC that allows the polarization spin vector of the electron and positron beams to be tuned independently for two Interaction Regions (IR). The correct spin direction for a particular IR can be selected by directing the beam into one of two parallel spin rotation beam lines located between the damping ring and the linac. With suitable fast kicker magnets, it is possible to rapidly switch between these parallel beam lines, so that polarized beams can be delivered to two IRs on a pulse train by pulse train basis. A similar scheme can be employed in the insertion beam line to the positron damping ring, to allow rapid helicity switching for polarized positrons

The integral of the spin-dependent structure function g1p and the Ellis-Jaffe sum rule

Hughes VW, Papavassiliou V, Piegaia R, Schüler KP, Baum G. The integral of the spin-dependent structure function g1p and the Ellis-Jaffe sum rule. Phys.Lett. B. 1988;212(4):511-514

The photon structure function measurements from LEP

The present knowledge of the structure of the photon based on measurements of photon structure functions is discussed. This review covers QED structure functions and the hadronic structure function F_2^gamma.The present knowledge of the structure of the photon based on measurements of photon structure functions is discussed. This review covers QED structure functions and the hadronic structure function F_2^gamma

Optimierungsansätze zur Verbesserung von Nachhaltigkeit, Ressourceneffizienz und Tierwohl in ökologischen und konventionellen Betrieben im Netzwerk Pilotbetriebe

In a network of organic and conventional pilot farms with dairy and/or arable production in Germany (www.pilotbetriebe.de) aspects of sustainability, resource efficiency, animal health and welfare and economic aspects are analysed. This is based on on-farm assessments and on whole farm modelling. In the first interdisciplinary workshops on the project farms results were presented and scenarios were developed in a participatory approach by scientists, consultants and farmers to improve N, P and land use efficiency as well as dairy health and welfare. Typical areas of action to optimize sustainability in these aspects were identified on the farms, e.g., complete accounting of manure N (N balance), enrichment of crop rotations with clover grass and cover crops (humus balance), improving forage quality (productivity, nutritional imbalances), improvement of housing conditions and grazing access (animal health and welfare). Systematic integration and detection of interconnectedness of environmental performance of production, animal welfare, resource efficiency and productivity result in a new quality in development of farm concepts

Measurement of Longitudinal Spin Transfer to Lambda Hyperons in Deep-Inelastic Lepton Scattering

Spin transfer in deep-inelastic Lambda electroproduction has been studied with the HERMES detector using the 27.6 GeV polarized positron beam in the HERA storage ring. For an average fractional energy transfer = 0.45, the longitudinal spin transfer from the virtual photon to the Lambda has been extracted. The spin transfer along the Lambda momentum direction is found to be 0.11 +/- 0.17 (stat) +/- 0.03 (sys); similar values are found for other possible choices for the longitudinal spin direction of the Lambda. This result is the most precise value obtained to date from deep-inelastic scattering with charged lepton beams, and is sensitive to polarized up quark fragmentation to hyperon states. The experimental result is found to be in general agreement with various models of the Lambda spin content, and is consistent with the assumption of helicity conservation in the fragmentation process.Comment: 8 pages, 3 figures; new version has an expanded discussion and small format change

Fur in Magnetospirillum gryphiswaldense Influences Magnetosomes Formation and Directly Regulates the Genes Involved in Iron and Oxygen Metabolism

Magnetospirillum gryphiswaldense strain MSR-1 has the unique capability of taking up large amounts of iron and synthesizing magnetosomes (intracellular magnetic particles composed of Fe3O4). The unusual high iron content of MSR-1 makes it a useful model for studying biological mechanisms of iron uptake and homeostasis. The ferric uptake regulator (Fur) protein plays a key role in maintaining iron homeostasis in many bacteria. We identified and characterized a fur-homologous gene (MGR_1314) in MSR-1. MGR_1314 was able to complement a fur mutant of E. coli in iron-responsive manner in vivo. We constructed a fur mutant strain of MSR-1. In comparison to wild-type MSR-1, the mutant strain had lower magnetosome formation, and was more sensitive to hydrogen peroxide and streptonigrin, indicating higher intracellular free iron content. Quantitative real-time RT-PCR and chromatin immunoprecipitation analyses indicated that Fur protein directly regulates expression of several key genes involved in iron transport and oxygen metabolism, in addition it also functions in magnetosome formation in M. gryphiswaldense

Observation of a Single-Spin Azimuthal Asymmetry in Semi-Inclusive Pion Electro-Production

Single-spin asymmetries for semi-inclusive pion production in deep-inelastic scattering have been measured for the first time. A significant target-spin asymmetry of the distribution in the azimuthal angle phi of the pion relative to the lepton scattering plane was observed for pi+ electro-production on a longitudinally polarized hydrogen target. The corresponding analyzing power in the sin(phi) moment of the cross section is 0.022 +/- 0.005 +/- 0.003. This result can be interpreted as the effect of terms in the cross section involving chiral-odd spin distribution functions in combination with a time-reversal-odd fragmentation function that is sensitive to the transverse polarization of the fragmenting quark.Comment: 5 pages of RevTex, 3 ps figures, 2 table

Beam-Induced Nuclear Depolarisation in a Gaseous Polarised Hydrogen Target

Spin-polarised atomic hydrogen is used as a gaseous polarised proton target in high energy and nuclear physics experiments operating with internal beams in storage rings. When such beams are intense and bunched, this type of target can be depolarised by a resonant interaction with the transient magnetic field generated by the beam bunches. This effect has been studied with the HERA positron beam in the HERMES experiment at DESY. Resonances have been observed and a simple analytic model has been used to explain their shape and position. Operating conditions for the experiment have been found where there is no significant target depolarisation due to this effect.Comment: REVTEX, 6 pages, 5 figure

Flavor decomposition of the sea quark helicity distributions in the nucleon from semi-inclusive deep-inelastic scattering

Double-spin asymmetries of semi-inclusive cross sections for the production of identified pions and kaons have been measured in deep-inelastic scattering of polarized positrons on a polarized deuterium target. Five helicity distributions including those for three sea quark flavors were extracted from these data together with re-analyzed previous data for identified pions from a hydrogen target. These distributions are consistent with zero for all three sea flavors. A recently predicted flavor asymmetry in the polarization of the light quark sea appears to be disfavored by the data.Comment: 5 pages, 3 figure