107543476
Design of the preinjector for the CERN RFQ2 project
115300845
Status and first beam measurements on the CERN RFQ
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.
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.
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.
102555920
The LHC Lead Ion Injector Chain
122396660
Theoretical Expectations for Mass Scales of the Fourth Generation and Higgs Bosons
We discuss two classes of theories that have something to say about fourth generation quark and lepton masses (as well as Higgs). One is based upon universality of low energy parameters as determined by the renormalization group: infra-red fixed points. The other is a toy model of geometric heirarchy which may arise in a novel scheme of dimensional reduction without compactification.
122741754
Are There Significant Gravitational Corrections to the Unification Scale
Abstract Higher dimension operators may be induced in the lagrangian of a unified theory by gravity. We find that c tr( G μv G μv H )/ M Planck can lead to substantial corrections to the unification scale. For ordinary SU(5) a second solution unifying at 10 17 GeV can exist which has no observable proton decay but an unacceptable value of sin 2 θ w . Analogous effects in supersymmetry, however, can lead to enormous corrections. We find that supersymmetric SU(5) can unify anywhere between 5 × 10 16 M X 18 GeV with an acceptable sin 2 θ w for | c | ⩽ 1.0.
14139978
THE DIFFRACTIVE QUANTUM LIMITS OF PARTICLE COLLIDERS
Quantum Mechanics places limits on achievable transverse beam spot sizes of particle accelerators. We estimate this limit for a linear collider to be \Delta x > \hbar c f/E\delta_0 where f is the final focal length, E the beam energy, and \delta_0 the intrinsic transverse Gaussian width of the electron wave-function. \delta_0 is determined in the phase space damping rings, and we find \delta_0 \approx \sqrt{\hbar c /eB} where B is the typical wiggler magnetic field strength in this system. For the NLC \delta_0 = 25 nm, and \Delta x = 0.06 nm, about two orders of magnitude smaller than the design goal. We can recover a crude estimate of the classical result when we include radiative relaxation effects. We also consider a synchrotron and obtain \Delta x > \sqrt{\hbar c f/E} = O(1.0) nm. We discuss formulation of quantum beam optics relevant to these issues.
119870151
A naturally heavy fourth generation neutrino
Abstract We propose that there exists a fourth generation, all neutrinos have Dirac masses of order the corresponding charge lepton partner, and right-handed neutrinos have Majorana masses of order the weak scale. The see-saw mechanism then implies the light neutrino masses are O( mM lepton 2 / M ), while a fourth generation neutrino is heavy with mass O( M )∼O( M w ), and would not have been seen in the Z 0 width a LEP. Such a solution appears to be compatile with all known phenomenological and cosmological constraints, and predicts masses for neutrinos near their current upper bounds.
15093335
Topcolor assisted technicolor
A condensate, tt, arising from O(TeV) scale “topcolor”, in addition to technicolor (and ETC) may naturally explain the gauge hierarchy, the large top quark mass, and contains a rich system of testable consequences. A triplet of strongly coupled pseudo-Nambu-Goldstone bosons, “top-pions”, near the top mass scale is a generic prediction of the models. A new class of technicolor schemes and associated phenomenology is suggested in this approach.