Phase-shift analysis is a commonly used technique to extract the scattering amplitudes of a two-body strong-interaction scattering process from the experimentally measured quantities | total cross-section, di erential cross-section, polarization and spin-correlation parameters. However, at a xed energy, all the scattering amplitudes can be multiplied by an arbitrary angle-dep phase-factor without a ecting the measurables. It would seem then that the phase of the..

In a previous paper we have shown that in quantum chromodynamics the gluon propagator vanishes in the infrared limit, while the ghost propagator is more singular than a simple pole. These results were obtained after angular averaging, but in the current paper we go beyond this approximation and perform an exact calculation of the angular integrals. The powers of the infrared behaviour of the propagators are changed substantially. We find the very intriguing result that the gluon propagator vanishes in the (...) infrared exactly like p2, whilst the ghost propagator is exactly as singular as 1/p4. We also find that the value of the infrared fixed point of the QCD coupling is much decreased from the y-max estimate: it is now equal to 4π/3. Following a recent study by von Smekal et al.[1], we analyzed in Ref.[2] the coupled Dyson- Schwinger equations for the gluon and ghost form factors F and G. The approximations were two-fold: firstly the vertices were taken bare, and secondly angular averaging was introduced (the so-called y-max approximation). Deferring to later work an improvement of the vertices. (shrink)

quantum electrodynamics. In quasilinear approximation, the integral equation is solved by Mellin transformation, followed by the calculation of the Muskhelishvili index of the resultant singular integral operator.

Although classical probability theory, as it is encapsulated in the axioms of Kolmogorov and in his criterion for the independence of two events, can consistently be employed in quantum mechanics, this can only be accomplished at an exorbitant price. By considering first the classic two‐slit experiment, and then the passage of one photon through three polarizers, the applicability of Kolmogorov's last axiom is called into question, but the standard rebuff of the Copenhagen interpretation is shown to be adequate to this (...) challenge. In the EPR experiment of Aspect, and the violation of the Bell inequalities, the matter is more delicate: it is not directly Kolmogorov's last axiom, but rather his criterion of independence that is at issue. It is explained how two events with space‐like separation cannot be independent in Kolmogorov's sense, even in the presence of hidden variables. The escape route of supposing the variables to be nonlocal, with a heavy metaphysical ballast of holism, which however is cosmically censored to prevent superluminal information transfer, has all the trappings of an ad hoc makeshift. The adoption of quantum mechanical probability, which does not obey the rules of Kolmogorov, but does survive empirical testing in terms of relative frequencies of events, is more economical. The solution is simple: correlations obey the rules of quantum mechanics and probability is a theory laden concept that is tested by, but not defined in terms of, the relative frequency of selected classes of events. Quantum mechanics appears to be nonlocal only if one tries to force it into a classical, realist straitjacket. However, this is a shortcoming of the straitjacket: it is not a property of quantum mechanics. That follows from the fact that a Bell telephone does not work! (shrink)