Results 1 - 10 of 14750
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[en] Adopting the q-theory approach to the cosmological constant problem, a simple field-theoretic model is presented which generates an effective cosmological constant (remnant vacuum energy density) of the observed order of magnitude, Λeff∼(meV)4, if there exist new TeV-scale ultramassive particles with electroweak interactions. The model is simple, in the sense that it involves only a few types of fields and two energy scales, the gravitational energy scale EPlanck∼1015 TeV and the electroweak (new-physics) energy scale Eew∼1-10 TeV.
[en] We construct ultraviolet-finite infinite-component field theories. In particular we find an infinite-component generalization of the Yang-Mills theory having an ultraviolet fixed point. We show that the infinite-component field theory with a mass for the first excitation M≤1--10 TeV solves the hierarchy problem
[en] In a bold move to boost US high energy physics. President Reagan has approved construction of the world's largest particle accelerator, the Superconducting Supercollider, SSC. With the requested start in Financial Year 1988, the Supercollider could be completed in 1996. The actual timetable depends on Congressional approval and actual levels of funding
[en] We use stellar dynamics arguments to constrain the relevant parameters of unparticle-inspired models of gravity. We show that resulting bounds do constrain the parameters of the theory of unparticles, as far as its energy scale satisfies the condition ΛU≥1 TeV and dU is close to unity.
[en] The acoustic method of determination of the efficiency of charged particle beam deflection by a bended crystal is discussed. The method relies on measurement of the amplitude of an acoustic signal excited by channeling particles. The sensitivity of the method for 10 TeV proton beams is estimated. It made up about 106 particles per pulse. 7 refs
[en] Time structure of electromagnetic cascade showers is calculated by Monte Carlo method in spatialy 3-dimensional condition, using newly obtained general solutions of Yang's equation. Instantaneous picture of shower, or lateral and longitudinal distribution of shower particles at a fixed time, in shower stages of rise, max and fall is indicated for a typical event of E0 = 0.81 TeV. Averaged feature of shower disc is also discussed from mean delay and thickness of it, and arrival time distributions at various distances from shower axis. (author)
[en] Results are reported from an experimental investigation of the electrodynamic characteristics of an accelerating structure with transverse rods and drift tubes for the fundamental and higher passbands. The studies are carried out in order to design transverse rod structures for a 3-TeV accelerator/storage ring facility with allowance for the design constraints and beam stability requirements
[en] We investigate the phenomenology of the light charged and neutral scalars in Inert Doublet Model at future e"+e"− colliders with center of mass energies of 0.5 and 1 TeV, and integrated luminosity of 500 fb"−"1. The analysis covers two production processes, e"+e"−→H"+H"− and e"+e"−→AH, and consists of signal selections, cross section determinations as well as dark matter mass measurements. Several benchmark points are studied with focus on H"±→W"±H and A→ZH decays. It is concluded that the signal will be well observable in different final states allowing for mass determination of all new scalars with statistical precision of the order of few hundred MeV.
[en] This report discusses the suitability of four novel particle acceleration technologies for multi-TeV particle physics machines: laser driven linear accelerators (linac), plasma beat-wave devices, plasma wakefield devices, and switched power and cavity wakefield linacs. The report begins with the derivation of beam parameters practical for multi-TeV devices. Electromagnetic field breakdown of materials is reviewed. The two-beam accelerator scheme for using a free electron laser as the driver is discussed. The options recommended and the conclusions reached reflect the importance of cost. We recommend that more effort be invested in achieving a self-consistent range of TeV accelerator design parameters. Beat-wave devices have promise for 1-100 GeV applications and, while not directly scalable to TeV designs, the current generation of ideas are encouraging for the TeV regime. In particular, surfatrons, finite-angle optical mixing devices, plasma grating accelerator, and the Raman forward cascade schemes all deserve more complete analysis. The exploitation of standard linac geometry operated in an unconventional mode is in a phase of rapid evolution. While conceptual projects abound, there are no complete designs. We recommend that a fraction of sponsored research be devoted to this approach. Wakefield devices offer a great deal of potential; trades among their benefits and constraints are derived and discussed herein. The study of field limitation processes has received inadequate attention; this limits experiment designers. The costs of future experiments are such that investment in understanding these processes is prudent. 34 refs., 12 figs., 3 tabs
[en] Detailed designs exist at present for linear colliders in the 0.5-1.0 TeV center-of-mass energy range. For linear colliders driven by discrete rf sources (klystrons), the rf operating frequencies range from 1.3 GHz to 14 GHz, and the unloaded accelerating gradients from 21 MV/m to 100 MV/m. Except for the collider design at 1.3 GHz (TESLA) which uses superconducting accelerating structures, the accelerating gradients vary roughly linearly with the rf frequency. This correlation between gradient and frequency follows from the necessity to keep the ac open-quotes wall plugclose quotes power within reasonable bounds. For linear colliders at energies of 5 TeV and above, even higher accelerating gradients and rf operating frequencies will be required if both the total machine length and ac power are to be kept within reasonable limits. An rf system for a 5 TeV collider operating at 34 GHz is outlined, and it is shown that there are reasonable candidates for microwave tube sources which, together with rf pulse compression, are capable of supplying the required rf power. Some possibilities for a 15 TeV collider at 91 GHz are briefly discussed