6 research outputs found
Auration of Ru3(m-H)(m3-C2H)(CO)9: tetrahedral and butterfly isomers of AuRu3(m-H)(m3-HC2H)(CO)9(PPh3) and related chemistry
No full textTreatment of [Ru3(µ-H)(µ3-C2H)(CO)9] 1 with K[BHBus3] followed by auration with [AuCl(PPh3)] gave the crystallographically characterised complexes [AuRu3(µ-H)(µ3-C2H2)(CO)9(PPh3)] 2, [Au2Ru3(µ3-CCH2)(CO)9(PPh3)2] 3 and [Ru3(µ-H){µ3-CHCHC(OH)}(CO)8(PPh3)] 4. Complex 2 crystallises in a dark red form, in which the AuRu3 core forms a tetrahedron, and a yellow form, in which the AuRu3 core has a butterfly structure; the C2H2 ligand is 212 co-ordinated to the Ru3 face in both. In 3 the Au2Ru3 core has a distorted square pyramidal conformation, with the CCH2 ligand attached to the Ru3 face. Complex 4 contains a hydroxyallyl ligand spanning the Ru3 core.Michael I. Bruce, Natasha N. Zaitseva, Brian W. Skelton and Allan H. Whit
Differential cross sections and recoil polarizations for the reaction γp→K<sup>+</sup>Σ<sup>0</sup>
No full textHigh-statistics measurements of differential cross sections and recoil polarizations for the reaction γp→K+Σ0 have been obtained using the CLAS detector at Jefferson Lab. We cover center-of-mass energies (√s) from 1.69 to 2.84 GeV, with an extensive coverage in the K+ production angle. Independent measurements were made using the K+pπ-(γ) and K+p(π-,γ) final-state topologies, and were found to exhibit good agreement. Our differential cross sections show good agreement with earlier CLAS, SAPHIR, and LEPS results, while offering better statistical precision and a 300-MeV increase in √s coverage. Above √s≈2.5 GeV, t- and u-channel Regge scaling behavior can be seen at forward and backward angles, respectively. Our recoil polarization (PΣ) measurements represent a substantial increase in kinematic coverage and enhanced precision over previous world data. At forward angles, we find that PΣ is of the same order of magnitude but opposite sign as PΛ, in agreement with the static SU(6) quark model prediction of PΣ≈-PΛ. This expectation is violated in some mid- and backward-angle kinematic regimes, where PΣ and PΛ are of similar magnitudes but also have the same signs. In conjunction with several other meson photoproduction results recently published by CLAS, the present data will help constrain the partial-wave analyses being performed to search for missing baryon resonances.</p
Spin and parity measurement of the Λ(1405) baryon
No full textA determination of the spin and parity of the Λ(1405) is presented using photoproduction data from the CLAS detector at Jefferson Lab. The reaction γ+p→K++Λ(1405) is analyzed in the decay channel Λ(1405)→Σ++π−, where the decay distribution to Σ+π− and the variation of the Σ+ polarization with respect to the Λ(1405) polarization direction determines the parity. The Λ(1405) is produced, in the energy range 2.55</p
Differential photoproduction cross sections of the Σ0(1385), Λ(1405), and Λ(1520)
No full textWe report the exclusive photoproduction cross sections for the Σ0(1385), Λ(1405), and Λ(1520) in the reactions γ+p→K++Y∗ using the CLAS detector for energies from near the respective production thresholds up to a center-of-mass energy W of 2.85 GeV. The differential cross sections are integrated to give the total exclusive cross sections for each hyperon. Comparisons are made to current theoretical models based on the effective-Lagrangian approach and fit to previous data. The accuracy of these models is seen to vary widely. The cross sections for the Λ(1405) region are strikingly different for the Σ+π−, Σ0π0, and Σ−π+ decay channels, indicating the effect of isospin interference, especially at W values close to the threshold.</p
Measurement of the Σπ photoproduction line shapes near the Λ(1405)
No full textThe reaction γ+p→K++Σ+π was used to determine the invariant mass distributions or “line shapes” of the Σ+π−, Σ−π+, and Σ0π0 final states, from threshold at 1328 MeV/c2 through the mass range of the Λ(1405) and the Λ(1520). The measurements were made with the CLAS system at Jefferson Lab using tagged real photons, for center-of-mass energies 1.95</p
FIGURES 1–12 in A study on the genus Compsidolon Reuter, 1899 from China (Hemiptera: Heteroptera: Miridae: Phylinae), with descriptions of three new species
No full textFIGURES 1–12. Adult habitus views of Compsidolon spp. 1. C. ailaoshanensis (male); 2. C. ailaoshanensis (female); 3. C. eximium (male); 4. C. eximium (female); 5. C. flavidum (male); 6. C. flavidum (female); 7. C. furcillatum (male); 8. C. furcillatum (female); 9. C. kerzhneri (male); 10. C. kerzhneri (female); 11. C. nebulosum (male); 12. C. nebulosum (female)Published as part of Li, Xiao-Ming & Liu, Guo-Qing, 2014, A study on the genus Compsidolon Reuter, 1899 from China (Hemiptera: Heteroptera: Miridae: Phylinae), with descriptions of three new species, pp. 469-483 in Zootaxa 3784 (4) on page 470, DOI: 10.11646/zootaxa.3784.4.6, http://zenodo.org/record/22531
