Applying generalized Pad\'e approximants in analytic QCD models

A method of resummation of truncated perturbation series, related to diagonal Pad\'e approximants but giving results independent of the renormalization scale, was developed more than ten years ago by us with a view of applying it in perturbative QCD. We now apply this method in analytic QCD models, i.e., models where the running coupling has no unphysical singularities, and we show that the method has attractive features such as a rapid convergence. The method can be regarded as a generalization of the scale-setting methods of Stevenson, Grunberg, and Brodsky-Lepage-Mackenzie. The method involves the fixing of various scales and weight coefficients via an auxiliary construction of diagonal Pad\'e approximant. In low-energy QCD observables, some of these scales become sometimes low at high order, which prevents the method from being effective in perturbative QCD where the coupling has unphysical singularities at low spacelike momenta. There are no such problems in analytic QCD.Comment: 14 pages; extended presentation of the analytic QCD models in Sec.IV; two references added ([37,38]); version to appear in Phys.Rev.

The New Particles-a Study in Nonrelativistic Versus Relativistic Physics. 2. Decays of the Charmonium States

Kögerler R. The New Particles-a Study in Nonrelativistic Versus Relativistic Physics. 2. Decays of the Charmonium States. ACTA PHYS AUSTRIACA. 1978;48(4):317-339

QUANTUM CHROMODYNAMICS AND HEAVY QUARKS. (IN GERMAN)

Kögerler R. QUANTUM CHROMODYNAMICS AND HEAVY QUARKS. (IN GERMAN). Phys.Bl. 1979;35:588-597

THE BELL THEOREM

Kögerler R. THE BELL THEOREM. 1986

ELECTROWEAK INTERACTIONS IN COMPOSITE MODELS: PHENOMENOLOGICAL ASPECTS

Kögerler R. ELECTROWEAK INTERACTIONS IN COMPOSITE MODELS: PHENOMENOLOGICAL ASPECTS. Presented at the SPIRES Conference C82/09/28

Pair production by deep inelastic hadron-hadron collision

A Regge analysis of the rho + rho '+q - forward scattering is used to study the behaviour of muon-pair production by inelastic hadron-hadron collision in different Regge-limits. Regge-hypothesis and factorization assumption lead to a natural interpretation for both the slope and the precise functional dependence of the data of the BNL- Columbia experiment. In addition it is shown that a lot of higher order diagrams will contribute considerably at energies available in the CERN-ISR

The New Particles: A Study in Nonrelativistic Versus Relativistic Physics. 1. Theoretical Preliminaries and the Charmonium Spectrum

Kögerler R. The New Particles: A Study in Nonrelativistic Versus Relativistic Physics. 1. Theoretical Preliminaries and the Charmonium Spectrum. ACTA PHYS AUSTRIACA. 1978;48(3):233-255

MASS-SPECTRUM OF P-WAVE MESONS

GUPTA V, Kögerler R. MASS-SPECTRUM OF P-WAVE MESONS. ZEITSCHRIFT FUR PHYSIK C-PARTICLES AND FIELDS. 1988;41(2):277-286

Sum Rules for Elastic gamma Gamma Scattering and Meson Decays in Two Photons

Grassberger P, Kögerler R. Sum Rules for Elastic gamma Gamma Scattering and Meson Decays in Two Photons. Nucl. Phys. B. 1976;106(3):451-460