115473197
Pion exchange contribution to baryon magnetic moments in QCD:an apparent paradox and its solution
120776511
The non-relativistic quark model
The classification scheme and decay properties of hadron states are investigated in the framework of the non relativistic quark model. The main successes and the unsolved difficulties of the model are presented indicating the future work which could be done to understand and exploit the non-relativistic quark ideas.РезюмеИсследованы схема классификации и распадные свойства адронов в рамках статической модели кварков. Изложены главные успехи и нерешенные проблемы модели, указывая задачи, которые должны быть решены для лучшего понимания и использования нерелятивистских идей.
124837005
SEARCH FOR QUARKS WITH THE FERROMAGNETIC LEVITATION ELECTROMETER
119592224
New Results in the Search of Quarks in Matter by the Magnetic Levitation Electrometer
Abstract The results of many runs performed levitating in succession several spheres without opening the levitation chamber show the existence of an additional (magneto-electric) force acting on the sphere. Ignoring this force in the analysis of the data produces “spurious” fractional charges.
14665617
Comment on "Chiral symmetry and the intrinsic structure of the nucleon"- by D.B.Leinweber,A.W.Thomas and R.D.Young
Some remarks are presented on a recent paper (Leinweber,Thomas and Young, Phys.Rev.Lett. 86, 5011, 2001). In particular a statement of the above paper on the fact that the ratio between the magnetic moments of proton and neutron should remain constant at -3/2, independent of the change of the quark mass is discussed on the basis of the general parameterization.
120916653
The relation between QCD and constituent quark models
5752960
THE CERN DETECTOR SAFETY SYSTEM FOR THE LHC EXPERIMENTS
The Detector Safety System (DSS), developed at CERN in common for the four LHC experiments under the auspices of the Joint Controls Project (JCOP), will be responsible for assuring the equipment protection for these experiments. Therefore, the DSS requires a high degree of both availability and reliability. It is composed of a Front-end and a Back-end part. The Front-end is based on a redundant Siemens PLC, to which the safetycritical part of the DSS task is delegated. The PLC Frontend is capable of running autonomously and of automatically taking predefined protective actions whenever required. It is supervised and configured by the CERN-chosen PVSS SCADA system via a Siemens OPC server. The supervisory layer provides the operator with a status display and with limited online reconfiguration capabilities. Configuration of the code running in the PLCs is completely data driven via the contents of a “Configuration Database”. Thus, the DSS can easily adapt to the different and constantly evolving requirements of the LHC experiments during their construction, commissioning and exploitation phases. Currently, the DSS is being installed and commissioned for the construction of the CMS and LHCb experiments.
12798237
Overview of LEP operation in 1998
After the installation of 32 additional RF cavities in the 1997-1998 shutdown LEP was operated at a beam energy of 94.5 GeV. The total integrated luminosity for the year 1998 clearly surpassed its target and reached 198 pb/sup -1/. Vertical beam-beam tuneshifts of more than 0.07 were obtained. The performance did not seem to be beam-beam limited, but the total beam current was limited by power dissipation problems to around 6 mA. A high phase advance optics (102/spl deg/, 90/spl deg/), with a smaller natural emittance, was used for regular operation in 1998. This contributed to the excellent performance of LEP, together with the further reduction of both the horizontal and vertical beta function at the interaction points. No dynamic aperture problems were encountered.
59433578
Electron-positron collisions at 209 GeV in LEP
The Large Electron-Positron Collider (LEP) at CERN closed down in November 2000. During the year 2000 electron-positron collisions were established at centre-of-mass energies of up to 209 GeV. The energy reach of LEP was thus extended by another 7 GeV compared to the year 1999. At the same time the luminosity production was kept high and the total delivered luminosity for the year was 233 pb/sup -1/. High beam energy and high luminosity extended the discovery reach of LEP. The successful energy increase of LEP is analysed and the operation and performance in the regime of ultra-strong damping is described.
59698437
The CERN/SL XDataviewer: An Interactive Graphical Tool for Data Visualization and Editing
As a result of many years of successive refinements, the CERN/SL Xdataviewer tool has reached its final stage. This graphical tool was especially developed to plot monoor bi-dimensional arrays of data, and to interact with them, in many different ways. Many pages of graphical information can be handled by the program, in a loose hierarchy of Views, Graphs and Plots objects. Data can be displayed, and interacted with, both in graphical and in text format. Sophisticated built-in Zoom and Data Editing capability is implemented, as well as a flexible Data Output generation facility. A complete C Callable Interface is provided, including a mechanism for feeding back the Application Program with the selections made by the User in the Data Display part. The tool has been written in C language, making use of the standard X Window libraries (Xlib,Xt,Motif). It can be run as a stand alone process, communicating with the Application Program via a shared memory, or it can be embedded in the Application Program itself.
55438680
THE ELECTRICAL CIRCUIT DESCRIPTION FOR THE LHC
The LHC is a very complex machine, made of about 8000 superconducting magnets along a circumference of 26.7 km. The magnets are powered in about 1700 different electrical circuits with currents ranging from 60 A (for small corrector magnets) up to 13 kA for the main dipoles and quadrupoles. The layout of the powering system reflects the complexity of the accelerator. About 80000 high current connections will have to be made. A minor fault in a circuit or one of the superconducting connections would have severe consequences for accelerator operation. For the integration of the electrical equipment, for supporting the assembly and verifying the correctness of the electrical circuits, all relevant information should be included in one coherent database. A simple method for the description of the electrical circuits is proposed, while an associated tool is translating this input into database information and back, checking the circuit description at the same time for inconsistencies. Out of the database information, electrical drawings and detailed views of the electrical connections at every LHC interconnection point can be recreated. This paper describes the approach and outlines several possible applications.