Polarization in Hadronic \Lambda Hyperon Production and Chiral-Odd Twist-3 Distribution

Polarization of the \Lambda hyperon produced with a large transverse momentum in the unpolarized nucleon-nucleon collision is analyzed in the framework of QCD factorization. We focus on the mechanism in which the soft-gluon component of the chiral-odd spin-independent twist-3 quark distribution E_F(x,x) becomes a source of the polarized quark fragmenting into the polarized \Lambda. Our simple model estimate for this contribution indicates that it gives rise to a significant \Lambda polarization at large x_F. This is in parallel with the observation that the soft gluon pole mechanism gives rise to a large single transverse spin asymmetry in the pion production at x_F\to 1.Comment: 10 pages in LaTex + 5 figures in PS files. Phys. Rev. D in press. Title changed and some discussions adde

Topological magnetic structures of MnGe: a neutron diffraction and symmetry analysis study

From new neutron powder diffraction experiments on the chiral cubic ($P2{_1}3$) magnet manganese germanide MnGe, we analyse all of the possible crystal symmetry-allowed magnetic superstructures that are determined successfully from the data. The incommensurate propagation vectors $k$ of the magnetic structure are found to be aligned with the [100] cubic axes, and correspond to a magnetic periodicity of about 30 $\r{A}$ at 1.8 K. Several maximal crystallographic symmetry magnetic structures are found to fit the data equally well and are presented. These include topologically non-trivial magnetic hedgehog and "skyrmion" structures in multi-$k$ cubic 3+3 and orthorhombic 3+2 dimensional magnetic superspace groups respectively, with either potentially responsible for topological Hall effect [1]. The presence of microstrain-like peak broadening caused by the transition to the magnetically ordered state would seem to favour a "skyrmion"-like magnetic structure, though this does not rule out the cubic magnetic hedgehog structure. We also report on a new combined mechanochemical and solid-state chemical route to synthesise MnGe at ambient pressures and moderate temperatures, and compare with samples obtained by the traditional high pressure synthesis

Genotype Analysis of Partial Growth Hormone Gene (GH891│MspI) in Pesisir Cattle and Simmental-Pesisir Crossbred Cattle

Growth hormone gene that controls metabolism and body size of animals and polymorphism of the gene is known related to performance of livestock. Identification of gene polymorphisms was important to get early information to determine genetic markers associated with economically desirable traits. Genetic mapping is one of important characterizations in the selection process. Pesisir cattle is one of local cattle in Indonesia that are reared in West Sumatera and have become adaptive to local environment. The present study aimed to identify the genotype of Growth Hormone gene (GH891│MspI) of the Pesisir cattle and crossbred Simmental-Pesisir cattle (designated as SimPes) and relationship between growth performance (body weight and body size). The present study was conducted to 30 blood samples consisted of 15 Pesisir cattle and 15 SimPes cattle. Body weight and body size were measured at 12-18 months of age. The Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) method was used in this research. The results showed that there exist three variant genotypes (MspI-/-, MspI+/-, MspI+/+) and that allele frequencies of MspI- and MspI+ were 53.3% and 46.7%, respectively. Non-significant effect has found between GH's genotype and growth traits (Body measurement and body weight) in both of breed cattle. In conclusion, three variant genotypes (GH891│MspI) in Pesisir and SimPes (Simmental x Pesisir) cattle population were found and no significant effect on growth trait performance