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Carl E. Carlson

Publications and source records attributed to Carl E. Carlson.

94 records · Page 6Linked to original sources

Galactic Rotation Curves and Linear Potential Laws

We study the possibility that galactic rotation curves can be explained by a gravitational potential that contains a linear term as well as a Newtonian one. This hypothesis, suggested by conformal gravity, does allow good fits to the galactic rotation curves of the galaxies we study, which have a wide range of luminosities. However, the universality one might have expected of the parameter describing the strength of the linear potential does not emerge. Instead, a different regularity is seen.

astro-ph↗

The Bloom-Gilman Duality and Leading Logarithms

The existing inclusive electroproduction data base allow us a look at the issue of the relative behaviors of background and resonance excitations, a part of the Bloom-Gilman duality. These data lack accuracy at high Q^2, but establish PQCD scaling in the resonance region and even allow us a glimpse at the leading logarithmic corrections due to the gluon radiation and its possible quenching at large W and x. These should inspire better quality experimental tests at facilities like CEBAF II.

hep-ph↗

Leading-Log Effects in the Resonance Electroweak Form Factors

We study log corrections to inelastic scattering at high Bjorken x for Q^2 from 1 to 21 GeV^2. At issue is the presence of log corrections, which can be absent if high x scattering has damped gluon radiation. We find logarithmic correction of the scaling curve extrapolated to low Q^2 improves the duality between it and the resonance plus background data in the Delta region, indicating log corrections exist in the data. However, at W > 2 GeV and high x, the data shows a (1-x)^3 form. Log corrections in one situation but not in another can be reconciled by a W- or Q^2- dependent higher twist correction.

hep-ph↗

Non-factorization and the Decays B into J/psi + K(*)

Many known models, which generally use a factorization hypothesis, give a poor account of the decays B into J/psi + K(*). Usually there is a free overall factor, which is fit to the data, so that tests of the models rely upon ratios. The models tend to give too much K* compared to K and too much transverse polarization compared to longitudinal. Our microscopic calculations, which use perturbative QCD, do well for both ratios. A microscopic calculation allows us to see how well factorization, heavy quark symmetry, and other features of various models are working. In the present case, agreement with the experimental ratios is dependent upon a breakdown of factorization for one of the amplitudes.

hep-ph↗