122062189
Two years of real progress in European HEP networking : a CERN perspective
Abstract The last two years have been marked by real progress in networking in HEP. Home-made developments, studies and plans have given way to the use of real networks involving hundreds of HEP and other computers and based on externally produced software and hardware. Within the last year, the first generation of industrial software products following some of the international standards for networking have become available. Related developments are taking place in networking for on-line systems and indeed the LEP experiments are distinguished by their heavy and crucial reliance on both local and wide-area networks. This paper describes the progress made at CERN since the last two years and looks at perspectives for the future.
108010999
The development and use of a high speed packet switching network in a high-energy physics laboratory
107816989
Performance of the HPD minimum guidance systeme, pt 1
59824716
The use of the FOCUS system to monitor an experiment at the CERN intersecting storage rings
195705202
Local area networks for microcomputers
Abstract This paper analyses the ways in which modern high performance Local Area Networks (LANs) can be of use to microcomputers. It discusses some of the basic concepts of LANs, with special reference to international standards. It then presents ways in which LANs may be connected to, and used with microcomputers. Examples are given of existing applications.
119218778
Cosmological perturbations of a perfect fluid and noncommutative variables
We describe the linear cosmological perturbations of a perfect fluid at the level of an action, providing thus an alternative to the standard approach based only on the equations of motion. This action is suited not only to perfect fluids with a barotropic equation of state, but also to those for which the pressure depends on two thermodynamical variables. By quantizing the system we find that (1) some perturbation fields exhibit a noncommutativity quite analogous to the one observed for a charged particle moving in a strong magnetic field, (2) local curvature and pressure perturbations cannot be measured simultaneously, (3) ghosts appear if the null energy condition is violated.
123618410
Resuscitation of the three-scalar doublet model with spontaneous CP violation
We show that the three-scalar doublet model with spontaneous CP violation and natural flavor conservation can be made consistent with the recent measurements of e′/e provided an interesting hierarchy among the vacuum expetation values present in the model is assumed. Simultaneously ΔM(KL−KS), the e parameter and the electric dipole moment of the neutron are consistent with the experimental data.
120899275
A model for leptons and quarks
Abstract A composite model for leptons and quarks is constructed starting from two fundamental fermions and a scalar. The model satisfies a modified form of 't Hooft's anomaly equations and predicts three active generations of leptons and four generations of quarks.
120024076
Compactification with scalar fields
The role of scalar fields in compactification is emphasized. A scale-invariant six-dimensional interacting scalar field theory is studied in some detail. Compactificaton occurs even at the tree level, and we obtain a relation between the compactification size (a), vacuum expectation values of scalar fields (ν) and the λφ3 interaction strength, a2νλ = O(1). We also point out some subtleties in the derivation of the four-dimensional gauge symmetry in this context.
117864746
The Delta I = 1/2 Rule in the Large N Limit
The large-N limit is used to obtain a consistent picture of the K → ππ matrix elements. It is confirmed that the dominant Q6 penguin matrix elements are enhanced by an order of magnitude compared to those of the current-current operators and that this result is consistent with chiral perturbation theory. An additional enhancement of the penguin contributions is identified with respect to standard estimates which comes from an incomplete GIM cancellation above the charm quark mass. Performing the short-distance analysis to first nontrivial order in 1/N its validity and simplicity is demonstrated. Encouraging results are obtained for A(K → ππ) amplitudes and it is pointed out that further improvements can be obtained through the inclusion of the low-energy evolution which necessarily must be done in a meson rather than a quark picture.