123448496
Further results and evaluation of electron cooling experiments at LEAR
Abstract First electron cooling experiments were performed with 10 7 to 2×10 9 stored antiprotons of 50, 21 and 6 MeV at the Low Energy Antiproton Ring (LEAR) at CERN. Most effort was put into the study of the longitudinal cooling. Schottky pick-up signals were used to measure the equilibrium momentum spread and the longitudinal cooling time. From the equilibrium between stochastic heating and electron cooling the longitudinal friction force in the low 10 3 m/s relative velocity range could be deduced. This method was used also to increase the cooling force by improving the alignment between the antiproton and the electron beam. Some of the experimental data are compared with results of a simulation program for electron cooling (SPEC).
115300845
Status and first beam measurements on the CERN RFQ
55729922
Experiments on a 14.5 GHz ECR Source
A device for measuring the speed of the wind at medium altitude by the Doppler effect within the visible frequency range comprises a laser which emits pulses of light, a telescope which receives a scattered light and an interferometer used to measure the spectral shift of the scattered light in relation to the emitted pulse of light. The interferometer is a Fabry-Perot interferometer in which a part of one of the two mirrors of the interferometer is covered with an excess thickness of silica to form two separate filters. The spacing of the two mirrors and the excess thickness of silica are determined in such a manner that the pass bands of each one of the two filters thus constructed are centered on the flanks of the spectral distribution of the backscattered light.
119401628
The Electron Cooling Device for LEAR
The experiments1,2,3 in which low energetic protons were cooled by a “cold” electron beam have proved that this method is a very powerful technique to improve low energy beams and to increase their phase space density by several orders of magnitude in short times. The theoretical understanding of the cooling process is well advanced4,5,6. The applications of this technique, which was invented and developed in Novosibirsk, are manifold7. It seems to be clear that its main domain is the cooling of non-relativistic ions. However, also at extremely high energies, cooling of protons and antiprotons with stored electrons (cooled themselves by synchrotron radiation) can be contemplated8,9.
121894301
Studies on ECR4 for the CERN ion program
The CERN heavy ion community, and some other high energy physics experiments, are starting to demand other ions, both heavy and light, in addition to the traditional lead ions. Studies of the behavior of the afterglow for different operation modes of the ECR4 at CERN have been continued to try to understand the differences between pulsed afterglow and continuous operation, and their effect on ion yield and beam reproducibility. The progress in adapting the source and ion beam characteristics to meet the new demands will be presented, as will new information on voltage holding problems in the extraction.
102555920
The LHC Lead Ion Injector Chain
18534210
Geometrical Renormalization Groups: Perfect Deconstruction Actions
By combining two distinct renormalization group transformations, opposing scale transformations, we obtain a composite transformation which does not rescale the system, and drives it to a "geometrical" fixed point, controlling the effective geometry and locality. The latticized (deconstructed) action for an extra-dimensional field theory becomes a ``perfect action,'' with a linear ladder spectrum for N KK-modes.
4238450
A possible practical application of heavy quark physics
A POSSIBLE method for storing very large amounts of useable energy within small volumes is described here. Our proposal is based on the existence of two new, virtually stable, forms of matter that annihilate each other with enormous energy release, but neither of which annihilates ordinary matter (and can thus be stored easily). The existence of these new forms of matter is suggested1,2 by the phenomenology of heavy quarks and also by a large class of widely discussed unified field theories.
53579013
Observability of Higgs produced with top quarks and decaying to bottom quarks
The decay, H → bb, is dominant for a Standard Model Higgs boson in the mass range just above the exclusion limit of 114.4 GeV/c 2 reported by the LEP experiments. Unfortunately, an overwhelming abundance of b¯ b events arising from more mundane sources, together with the lack of precision inherent in the reconstruction of the Higgs mass, renders this decay modeaprioriundetectable in the case of direct Higgs production at the LHC. It is therefore of no small interest to investigate whether H → bb can be observed in those cases where the Higgs is produced in association with other massive particles. In this note, the results of a study of Higgs bosons produced in association with top quarks and decaying via H → bb are presented. The study was performed as realistically as possible by employing a full and detailed Monte Carlo simulation of the CMS detector followed by the application of trigger and reconstruction algorithms that were developed for use with real data. Important systematic effects resulting from such sources as the uncertainties in the jet energy scale and the estimated rates for correctly tagging b jets or mistagging non-b jets have been taken into account. The impact of large theoretical uncertainties in the cross sections for t tp lusN jets processes due to an absence of next-to-leading order calculations is also considered.
122222802
Can the hawking effect thaw a broken symmetry
Abstract A spontaneously broken symmetry is shown not to be restored as witnessed by accelerating (Rindler) observers. To one-loop thermal contributions appear only in differences between Minkowski and Rindler vacuum matrix elements. All observers obtain (up to coordinate transformations) the same matrix elements of physical operators. Identical effective potentials and order parameters are obtained by all observers.
122935123
Covariant functional Schrödinger formalism and application to the Hawking effect
Abstract We develop a manifestly, generally coordinate-covariant functional Schrodinger formalism. We study the usual problem of Hawking radiation in the Rindler coordinate system. The Hawking effect appears as a shift in the width of the ground-state wave functional relative to a true vacuum state in the low-momentum components. It can be a coherent rather than a thermal effect depending upon the choice of boundary conditions. We analyse the general d + 1 massive solution and discuss its strange features. For example, the d + 1particle number distribution is thermal but not isotropic due to a peculiar energy-momentum dispersion relation. We address a number of other conceptual issues.