Consistency determining fundamental constant

The fine structure constant a can be determined with the help of several methods. The most accurate test of QED involves the anomalous magnetic moment of the electron [40] and provides the most accurate way to determine a value for the fine structure constant. Recent progress in calculations of the helium fine structure has allowed one to expect that the comparison of experiment [23,24] and ongoing theoretical prediction [23] will provide us with a precise value of a. Since the values of the fundamental constants and, in particular, of the fine structure constant, can be reached in a number of different ways it is necessary to compare them. Some experiments can be correlated and the comparison is not trivial. A procedure to find the most precise value is called the adjustment of fundamental constants [39]. A more important target of the adjustment is to check the consistency of different precision experiments and to check if e.g. the bound state QED agrees with the electrical standards and solid state physics. 

The 1998 adjustment of the values of the fundamental physical constants has been carried out by the authors under the auspices of the CODATA Task Group on Fundamental Constants [1,2]. The purpose of the adjustment is to determine best values of various fundamental constants such as the fine-structure constant, Rydberg constant, Avogadro constant, Planck constant, electron mass, muon mass, as well as many others, that provide the greatest consistency among the most critical experiments based on relationships derived from condensed matter theory and quantum electrodynamics (QED) theory. The 1998 CODATA recommended values of the constants also may be found on the Web at physics.nist.gov/constants. 

The spectroscopic experiments in muonium, in particularly on the hyperfine and the ls-2s intervals, are closely inter-related with the determination of the muon magnetic anomaly through the fundamental relation = (1 -h a ) e/i/(2 7j c). The results from all experiments establish a self consistency requirement for QED and electroweak theorj and the set of fundamental constants involved (Fig. 5) The constants are the most stringently... 

The values of the fundamental constants and the theory of quantum electrodynamics (QED) are cl< ely coupled. This is evident from the fact that the constants appear as parameters in the theoreticjd expressions that describe the physical properties of particles and matter, and most of these theoretical expressions are derived from QED. In practice, values of the constants are determined by a consistent competrison of the relevant measurements and theoretical expressions involving those constants. Such a comparison is being carried out in order to provide CODATA recommended values of the constants for 1997. This review describes some of the advances that have been made since the last set of constants was recommended in 1986. As a result of these advances, there is a significant reduction in the uncertainty of a number of constants included in the set of 1997 recommended values. 

Basic physical theories and their application to other fields of science and technology always involve certain fundamental invariant quantities, called briefly fundamental constants. Well-known examples of such constants are the speed of light in vacuum, the elementary charge (electron charge), the mass of the electron, and so on. It is important to know the numerical values of the fundamental constants with the highest possible accuracy, because the attained accuracy determines the accuracy of the quantitative predictions of fundamental theories. Moreover, the accurate numerical values of the fundamental constants test the overall consistency and correctness of those theories. 

Templated mesoporous silica material MCM-41 [1] consists of hexagonal arrays of cylindrical pores with diameters between 1.5 and 20 nm, narrow pore size distributions and negligible pore networking. These properties make these materials ideal for fundamental studies aimed at determining the effect of surface forces, confinement and reduced dimensionality on the phase behavior of host molecules. The features of MCM-41 materials [2] make them suitable for a number of applications in catalysis, adsorption, optics, as low dielectric constant materials to insulate integrated circuits, and as host materials for polymers, nanoparticles and enzymes [2], The gas-liquid transition of adsorbates in templated mesoporous silica materials has been extoisively studied by experiment, theory and molecular simulation [3], From a molecular simulation viewpoint, a number of silica pore models have... 

---