Simple approximation for the starting-energy-independent two-body effective interaction with applications to 6Li

We apply the Lee-Suzuki iteration method to calculate the linked-folded diagram series for a new Nijmegen local NN potential. We obtain an exact starting-energy-independent effective two-body interaction for a multi-shell, no-core, harmonic-oscillator model space. It is found that the resulting effective-interaction matrix elements can be well approximated by the Brueckner G-matrix elements evaluated at starting energies selected in a simple way. These starting energies are closely related to the energies of the initial two-particle states in the ladder diagrams. The ``exact'' and approximate effective interactions are used to calculate the energy spectrum of 6Li in order to test the utility of the approximate form.Comment: 15 text pages and 2 PostScript figures (available upon request). University of Arizona preprint, Number unassigne

Shell-model calculations of neutrino scattering from 12C

Neutrino reaction cross-sections, $(\nu_\mu,\mu^-)$, $(\nu_e,e^-)$, $\mu$-capture and photoabsorption rates on $^{12}$C are computed within a large-basis shell-model framework, which included excitations up to $4\hbar\omega$. When ground-state correlations are included with an open $p$-shell the predictions of the calculations are in reasonable agreement with most of the experimental results for these reactions. Woods-Saxon radial wave functions are used, with their asymptotic forms matched to the experimental separation energies for bound states, and matched to a binding energy of 0.01 MeV for unbound states. For comparison purposes, some results are given for harmonic oscillator radial functions. Closest agreement between theory and experiment is achieved with unrestricted shell-model configurations and Woods-Saxon radial functions. We obtain for the neutrino-absorption inclusive cross sections: $\bar{\sigma} = 13.8 \times 10^{-40}$ cm$^2$ for the $(\nu_{\mu},\mu^{-})$ decay-in-flight flux in agreement with the LSND datum of $(12.4 \pm 1.8) \times 10^{-40}$ cm$^2$; and $\bar{\sigma} = 12.5 \times 10^{-42}$ cm$^2$ for the $(\nu_{e},e^{-})$ decay-at-rest flux, less than the experimental result of $(14.4 \pm 1.2) \times 10^{-42}$ cm$^2$.Comment: 19 pages. ReVTeX. No figure

Large-space shell-model calculations for light nuclei

An effective two-body interaction is constructed from a new Reid-like $NN$ potential for a large no-core space consisting of six major shells and is used to generate the shell-model properties for light nuclei from $A$=2 to 6. (For practical reasons, the model space is partially truncated for $A$=6.) Binding energies and other physical observables are calculated and compare favorably with experiment.Comment: prepared using LaTex, 21 manuscript pages, no figure

Final-State Phases in Charmed Meson Two-Body Nonleptonic Decays

Observed decay rates indicate large phase differences among the amplitudes for the charge states in $D \to \bar K \pi$ and $D \to \bar K^* \pi$ but relatively real amplitudes in the charge states for $D \to \bar K \rho$. This feature is traced using an SU(3) flavor analysis to a sign flip in the contribution of one of the amplitudes contributing to the latter processes in comparison with its contribution to the other two sets. This amplitude may be regarded as an effect of rescattering and is found to be of magnitude comparable to others contributing to charmed particle two-body nonleptonic decays.Comment: 19 pages, latex, 4 figures, to be submitted to Phys. Rev.

Strangeness nuclear physics: a critical review on selected topics

Selected topics in strangeness nuclear physics are critically reviewed. This includes production, structure and weak decay of $\Lambda$--Hypernuclei, the $\bar K$ nuclear interaction and the possible existence of $\bar K$ bound states in nuclei. Perspectives for future studies on these issues are also outlined.Comment: 63 pages, 51 figures, accepted for publication on European Physical Journal

Study of the Effect of Mold Corner Shape on the Initial Solidification Behavior of Molten Steel Using Mold Simulator

The chamfered mold with a typical corner shape (angle between the chamfered face and hot face is 45 deg) was applied to the mold simulator study in this paper, and the results were compared with the previous results from a well-developed right-angle mold simulator system. The results suggested that the designed chamfered structure would increase the thermal resistance and weaken the two-dimensional heat transfer around the mold corner, causing the homogeneity of the mold surface temperatures and heat fluxes. In addition, the chamfered structure can decrease the fluctuation of the steel level and the liquid slag flow around the meniscus at mold corner. The cooling intensities at different longitudinal sections of shell are close to each other due to the similar time-average solidification factors, which are 2.392 mm/s1/2 (section A-A: chamfered center), 2.372 mm/s1/2 (section B-B: 135 deg corner), and 2.380 mm/s1/2 (section D-D: face), respectively. For the same oscillation mark (OM), the heights of OM roots at different positions (profile L1 (face), profile L2 (135 deg corner), and profile L3 (chamfered center)) are very close to each other. The average value of height difference (HD) between two OMs roots for L1 and L2 is 0.22 mm, and for L2 and L3 is 0.38 mm. Finally, with the help of metallographic examination, the shapes of different hooks were also discussed

Observation of hard scattering in photoproduction events with a large rapidity gap at HERA

Events with a large rapidity gap and total transverse energy greater than 5 GeV have been observed in quasi-real photoproduction at HERA with the ZEUS detector. The distribution of these events as a function of the $\gamma p$ centre of mass energy is consistent with diffractive scattering. For total transverse energies above 12 GeV, the hadronic final states show predominantly a two-jet structure with each jet having a transverse energy greater than 4 GeV. For the two-jet events, little energy flow is found outside the jets. This observation is consistent with the hard scattering of a quasi-real photon with a colourless object in the proton.Comment: 19 pages, latex, 4 figures appended as uuencoded fil

Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio