Large p⊥ lepton production and the ψ(3100)

We determine the invariant cross section $\text{E}\text{d}\text{σ}\text{d}{}^3\text{p(s,x}{}_6\text{,pp}{}_{\mathrm{\perp }}\text{)}$ for pp→ψ(3100)+X near x₆=0 at NAL and ISR energies using the assumption that all large p_⊥ single leptons originate from the ψ. We adequately reproduce the single lepton data, and by suitable extrapolarion in x₆ ensure agreement with the NAL ψ production data (x₆?0.3). The magnitude of the resulting ψ production cross section is, however, roughly a factor of 3 larger than that observed by the recent CCRS-ISR experiment.     

Searching for the spin-0 leptons of supersymmetry

The production and subsequent decay of spin-0 electrons and muons in e⁺e^? annihilation leads to distinctive noncoplanar e⁺e^? or μ⁺μ^? production, with missing energy carried away by photinos or goldstinos. We give the cross section predicted by supersymmetry for creating pairs of these new spin-0 particles. Present e⁺e^? annihilation experiments imply that their masses must be larger than $\text{3}\text{1}\text{2}\text{GeV}\text{/c}{}^2$, and in the near future PETRA experiments will either observe them or raise this limit to ～15 GeV/c².     

High-energy fixed-angle elastic scattering

The leading behavior of high-energy, fixed-angle, hadron-hadron scattering is obtained in a model in which on-mass-shell colored quarks exchange colored gluons. The resultant differential cross sections are compared with the data, indicating that such a mechanism does not dominate the physical scattering process.     

Phenomenology of the production,decay, and detection of new hadronic states associated with supersymmetry

Supersymmetric theories involve spinorial partners for the gluons of QCD. If the symmetry breaking is such that they are massless or light, they probably combine with quarks to form families of new, relatively low-lying hadrinic states, which decay into ordinary hadrons and a new, neutrino-like particle. We discuss how present experiments can put limits on their production.     

Testing QCD

QCD is used to predict that the ratio of up to down quarks → 5 as x → 1 and the rigor of the proof and the underlying assumptions are discussed. Measuring $\text{σ}{}^{\mathrm{<mtext>v</mtext><mtext>?</mtext>}}\text{P}\text{σ}{}^{\mathrm{v}}\text{P}\text{as}\text{x → 1}$ gives the best experimental test of this prediction.     

Dark matter and the baryon asymmetry of the universe

We present a mechanism to generate the baryon asymmetry of the Universe which preserves the net baryon number created in the big bang. If dark matter particles carry baryon number Bx, and sigmaxannih相似文献   

The crystal and molecular structure of dichloro-(bis-1,2-diphenylphosphinoethane)platinum(II)

Crystals of PtCl₂(PPh₂)(CH₂)₂(PPh₂) (1), produced from attempts to prepare hydridochloroplatinum complexes, are monoclinic, space groupP2 ₁ /c, with four molecules in a unit cell of dimensionsa=11.478(3),b=13.263(2)c=16.343(3) Å, and =99.00(2)°. The structure was solved by the heavy-atom method and refined by block-diagonal least-squares calculations with anisotropicthermal parameters;R=0.048 andR=0.061 for 1843 observed reflections. The crystal structure contains discrete well-resolved molecules. The Pt atom has distorted square-planar coordination with Pt-P 2.208(6), Pt-Cl 2.355 and 2.341(6) Å distances, and Cl-Pt-Cl 90.2(2) and P-Pt-P 86.3(2)° angles.     

Accelerated degradation behaviour of poly(?-caprolactone) via melt blending with poly(aspartic acid-co-lactide) (PAL)

Poly(?-caprolactone) (PCL) has many favourable attributes for tissue engineering scaffold applications. A major drawback, however, is its slow degradation rate, typically greater than 3 years. In this study PCL was melt blended with a small percentage of poly(aspartic acid-co-lactide) (PAL) and the degradation behaviour was evaluated in phosphate buffer solution (PBS) at 37 °C. The addition of PAL was found to significantly enhance the degradation profile of PCL. Subsequent degradation behaviour was investigated in terms of the polymer's mechanical properties, molecular weight (M_w), mass changes and thermal characteristics. The results indicate that the addition of PAL accelerates the degradation of PCL, with 20% mass loss recorded after just 7 months in vitro for samples containing 8 wt% PAL. The corresponding pure PCL samples exhibited no mass loss over the same time period. In vitro assessment of PCL and PCL/PAL composites in tissue culture medium in the absence of cells revealed stable pH readings with time. SEM studies of cell/biomaterial interactions demonstrated biocompatibility of C₃H₁₀T_1/2 cells with PCL and PCL/PAL composites at all concentrations of PAL additive.