Subsolar noble gases in an acid-resistant residue of the EH5 chondrite St Mark's

Extract from the introduction: Enstatite chondrites have remarkable properties: they were formed in a reducing environment, they are putatively similar to precursor material of Earth, Venus, or Mercury, have a terrestrial oxygen isotopic composition and an uncommon noble gas signature [1-5]. Trapped noble gases in Echondrites are intermediate between solar and chondritic composition and consist of two components: Subsolar, enriched in Ar and Kr relative to Xe and Q-gas, possibly residing in enstatite, micro-vesicles or graphite within enstatite [6,7] and Q-gases [5,8]

Phase Q - A carrier for subsolar noble gases

We discuss noble gases in the E-chondrite St. Mark's indicating that the subsolar component does not exclusively reside in enstatite. Element and isotope abundances including He are presented. Fractionation probably took place prior to incorporation

Helium isotopic ratios in carbonaceous chondrites: Significant for the early solar nebula and circumstellar diamonds?

Stepwise etching of acid-resistant residues from carbonaceous chondrites yields a new, extraordinarily low He isotopic ratio for phase Q that might represent early solar nebula composition. A much lower ratio possibly characterizes He-P3 from circumstellar diamonds

On line etching of bulk EH5 St. Mark's – Radiogenic and subsolar noble gases

Introduction: On line etching is very useful to analyse noble gas components such as 'Q' or the solar wind [1, 2]. A bulk meteorite sample, however, has never been analysed by on line etching in order to characterise its complete noble gas inventory

Solar noble bases in enstatite chondrites and implications for the formation of the terrestrial planets

We report evidence for tiny amounts of - most likely primordial - noble gases with solar-like elemental and isotopic composition admixed to Q-type primordial noble gases in an E chondrite. We will discuss possible implications of this finding for terrestrial planet formation

The ingredients of the “Subsolar” noble gas component

On the basis of several experiments on separates of the EH5 chondrite St. Mark–s, we will argue that the 'subsolar' noble gas component is a mixture of solar-like, Q- and terrestrial noble gases

Bremsstrahlung Pair Production In Relativistic Heavy Ion Collision

We calculate production of electron- and muon-pairs by the bremsstrahlung process in hadron collisions and compare it with the dominant two-photon process. Results for the total cross section are given for proton-proton and heavy-ion collisions at energies of the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC).Comment: 6 pages, Latex, 9 figures using epsf-style. Accepted for publication in Z. Phys.

Hadron collider limits on anomalous WWγWW\gamma couplings

A next-to-leading log calculation of the reactions $pp$ and $p\overline{p}\rightarrow W^\pm\gamma X$ is presented including a tri-boson gauge coupling from non-Standard Model contributions. Two approaches are made for comparison. The first approach considers the tri-boson $WW\gamma$ coupling as being uniquely fixed by tree level unitarity at high energies to its Standard Model form and, consequently, suppresses the non-Standard Model contributions with form factors. The second approach is to ignore such considerations and calculate the contributions to non-Standard Model tri-boson gauge couplings without such suppressions. It is found that at Tevatron energies, the two approaches do not differ much in quantitative results, while at Large Hadron Collider (LHC) energies the two approaches give significantly different predictions for production rates. At the Tevatron and LHC, however, the sensitivity limits on the anomalous coupling of $WW\gamma$ are too weak to usefully constrain parameters in effective Lagrangian models.Comment: Revtex 23 pages + 8 figures, UIOWA-94-1

Mechanisms for Direct Breakup Reactions

We review some simple mechanisms of breakup in nuclear reactions. We mention the spectator breakup, which is described in the post-form DWBA. The relation to other formulations is also indicated. An especially important mechanism is Coulomb dissociation. It is a distinct advantage that the perturbation due to the electric field of the nucleus is exactly known. Therefore firm conclusions can be drawn from such measurements. Some new applications of Coulomb dissociation for nuclear astrophysics are discussed.Comment: 17 pages, 5 figures, to appear in the proceedings of the RCNP-TMU Symposium on Spins in Nuclear and Hadronic Reactions, October 16-18 199