e+e− → γ + Hadrons

We give the spectrum in momentum and angle of directly produced γ's in e⁺e^? → γ + hadrons, and show that in QCD if p_⊥² of the recoil hadron jet relative to the photon is large, the leading logarithmic corrections to the lowest order result are absent. This process is therefore of great value in learning whether QCD actually governs quark dynamics.     

QCD predictions for γγ annihilation to baryons

QCD predictions for large-momentum transfer cross sections of the type $\text{γγ →}\text{B}\text{B}\text{′}$ are given, for B and B′ any members of the baryon octet or decuplet, and all possible helicity combinations for photons and baryons.     

Advancements in internationally accepted standards for radiation processing

Three subcommittees of the American Society for Testing and Materials (ASTM) are developing standards on various aspects of radiation processing. Subcommittee E10.01 “Dosimetry for Radiation Processing” has published 9 standards on how to select and calibrate dosimeters, where to put them, how many to use, and how to use individual types of dosimeter systems. The group is also developing standards on how to use gamma, electron beam, and x-ray facilities for radiation processing, and a standard on how to treat dose uncertainties. Efforts are underway to promote inclusion of these standards into procedures now being developed by government agencies and by international groups such as the United Nations' International Consultative Group on Food Irradiation (ICGFI) in order to harmonize regulations and help avoid trade barriers.

Subcommittee F10.10 “Food Processing and Packaging” has completed standards on good irradiation practices for meat and poultry and for fresh fruits, and is developing similar standards for the irradiation of seafood and spices. These food-related standards are based on practices previously published by ICGFI.

Subcommittee E10.07 on “Radiation Dosimetry for Radiation Effects on Materials and Devices” principally develops standards for determining doses for radiation hardness testing of electronics. Some, including their standards on the Fricke and TLD dosimetry systems are equally useful in other radiation processing applications.     

Reactions of 2-indolylphosphines with Ru3(CO)12: cluster capping with mu 3,eta 2-indolylphosphine as an anionic six-electron P,N-donor ligand

Stepwise bidentate coordination of the novel indolylphosphine ligands HL (1, HL = P(C(6)H(5))(2)(C(9)H(8)N)(diphenyl-2-(3-methylindolyl)phosphine); 2, HL = P(C(6)H(5))(C(9)H(8)N)(2)(phenyldi-2-(3-methylindolyl)phosphine); and 3, HL = P(C(6)H(5))(C(17)H(12)N(2))(di(1H-3-indolyl)methane-(2,12)-phenylphosphine)) to the ruthenium cluster Ru(3)(CO)(12) is demonstrated. Reactions of 1-3 with Ru(3)(CO)(12) led to the formation of Ru(3)(CO)(11)(HL) (4-6), in which HL is mono-coordinated through the phosphorus atom. The X-ray structures of 4-6 show that the phosphorus atom is equatorially coordinated to the triruthenium core. In all cases, gentle heating of Ru(3)(CO)(11)(HL) resulted in the formation of Ru(3)(CO)(9)(mu-H)(mu(3),eta(2)-L)(7-9) in which the NH proton of the indolyl substituent had migrated to the ruthenium core to form a bridging hydride ligand. The X-ray structure of Ru(3)(CO)(9)(mu-H)[mu(3),eta(2)-P(C(6)H(5))(2)(C(9)H(7)N)] (7) shows the deprotonated nitrogen atom of the indolyl moiety bridging over the face of the triruthenium core, bonding to the two ruthenium metal centers to which the phosphorus atom is not bound. The phosphorus atom is forced to adopt an axial bonding mode due to the geometry of the indolylphosphine ligand. Cluster electron counting and X-ray data suggest that the indolylphosphine behaves as a six-electron ligand in this mode of coordination. Compounds 4-9 have been characterized by IR, (1)H, (13)C and (31)P NMR spectroscopy.