A test of a model t-matrix for direct reaction inelastic scattering

Differential cross sections and analyzing powers from the inelastic scattering of 65 MeV protons leading to the 1⁺T=0 (12.71 MeV) and 1⁺T = 1 (15.11 MeV) states in ¹²C have been analysed as tests of a model two-nucleon t-matrix.     

3β-methoxy-5α-cholestane-4β,5-diol and related compounds

The major product of acid-catalysed hydrolysis of 4α,5-epoxy-3β-methoxy-5α-cholestane (5) has been shown to be the allylic alcohol 9 (R = H) and not diol 10 as previously reported. A preparation of the latter compound, and of a number of cholestane derivatives with oxygen substituents in rings A and B, is described.     

Multiplicity structure of proton and kaon diffractive dissociation in 10 and 16 GeV/c K-p interactions

A new method to calculate diffractive mass spectra has been developed. It is applied to K^-p interactions at 10 and 16 GeV/c. Cross sections and mass spectra are given for the difractive dissociation processes p→(N+iπ) and K^-p→(K+iπ) for i = 1 to 5 and also summed over all multiplicities. In addition to the diffractive peak at low mass coming from low multiplicities, a long tail extending to high masses and high multiplicities has been found. The multiplicity structure of diffraction dissociation can be understood in the context of the two-step dynamical picture of Pokorsky and Van Hove.     

2:1:1 Resonance in the Quasi-Periodic Mathieu Equation

We present a small $ \ddot x + (\delta + \epsilon \cos t + \epsilon \cos \omega t) x=0 $ \ddot x + (\delta + \epsilon \cos t + \epsilon \cos \omega t) x=0      

Surface states due to deposited alkaline earth cations on ZnO

Surface states due to Be, Mg, Ca, Sr, and Ba ions deposited on ZnO as salts with varying anions have been examined, to make available a selection of nonvolatile surface states for later study, and to provide a relatively simple group of substitutional surface states that could be used to compare theories with experiment. The results indicate that Be⁺⁺ and Ba⁺⁺ additions lead to shallow acceptor levels, near or above the ZnO conduction band, while deeper acceptor levels (as low as 0.9 eV below the conduction band) are associated with Mg⁺⁺, Ca⁺⁺, and Sr⁺⁺ additions. The energy of the resulting surface state depends somewhat on whether the alkaline earth species is added as the hydroxide or the fluoride. There is evidence of a high density donor level at 1.1 eV below the conduction band perhaps associated with surface lattice oxygen or with OH^? groups. Arguments arepresented suggesting that the surface state is associated with the alkaline earth ions at lattice sites at the ZnO/additive interface, and some of the factors are discussed that must be considered in a theoretical model.     

Analysis of the ground configuration of Tm3+ in YVO4

An analysis has been made of the optical spectrum of Tm³⁺ in YVO₄ reported by K. D. Knoll. The approach taken was to describe the Tm³⁺ free ion as completely as possible and then to describe the effects of the crystal field on these levels. Parameters were obtained that gave an r.m.s. deviatioa of 10.6 cm^?1 in a least squares fit. In Knolls' earlier analysis, which did not describe the free ion adequately, several sets of parameters were given that are consistent with different portions of the spectrum. The results computed with our parameters gave a new interpretation of the ³F₄ and ³H₅ multiplets and gave g_∥ factors in good agreement with the measurements. The efiects of the hyperfine interaction and the spin-crystal field interaction on the energy levels resulted in displacements of smaller than 0.1 cm^?1.     

Study of proton dissociation into ΛK+ in 3-body final states at 10 and 16 GeV/c

Results are presented for p → (ΛK⁺) dissociation in the reactions K^?p → ΛK⁺K^? and and π^±p → ΛK⁺π^±at 10 and 16 GeV/c. The cross sections for the low-mass ΛK⁺ enhancement are compatible with the energy dependence σ ∝ p_lab^?0.3. The t′ spectra or the (ΛK⁺) threshold enhancement are exponential in shape. Its decay angular distribution reveals neither s-channel nor t-channel helicity conservation. The relative probabilities of the processes $\text{p}\text{→}\text{p, p}\text{→ (}\text{N}\text{π)}{}_{\mathrm{<mtext>I=</mtext><mtext>1</mtext><mtext>2</mtext>}}\text{and p}\text{→ (Λ}\text{K}{}^{\mathrm{+}}\text{)}$ dissociation are in the ratios 100 : 10 : 0.2, independent of the nature of the incident particle.