117318296
Relativistic Motion of Composite Systems with Nonrelativistic Internal Dynamics
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.
124837005
SEARCH FOR QUARKS WITH THE FERROMAGNETIC LEVITATION ELECTROMETER
120916653
The relation between QCD and constituent quark models
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.
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.
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.
56290660
The Software for the CERN Detector Safety System
The CERN Detector Safety System (DSS) has been developed to monitor the state of the LHC detectors and protect their components against emer gency situations which other less reliable systems could possibly fail to handle, or which were not co vered by any other system. The DSS consists of two main components: a PLC-based Front-End and a supervisor Back-End. The two parts communicate via the OPC mechanism. The Front-End is the core of the DSS, to which all the runtime safety-critical actions are delegated. These are encoded in an "Alarm-Action Matrix", that can be seen as a set of user-defined rules relating the Input Channels (analogue and digital senso rs) to the Output Channels (actuators, typically on/off interlock switches). One of the user requireme nts is the possibility of modifying these rules at any time, without stopping the system. New Input and Output Channels can also be incrementally added to the system without perturbing the prev iously existing part. To fulfil these requirements without detriment to the safety-critical part, the PLC software has been designed in a completely datadriven way. This approach allowed the PLC code to be kept as simple as possible and independent from the user-defined rules. The rules, as well as the parameteri zation for the Input and Output Channels, are stored into PLC "datablocks", whose contents drive the execution of the PLC code. The supervisor Back-End, based on the CERN-chosen PVSS SCADA system, represents both the “Configuration Interface” and the “Operator Display” for the DSS. The User is able to define and parameterize Input and Output Channels and to modify the set of rules defining the Alarm-Action Matrix. These modifications, after passing some c onsistency checks, are accepted by the Back-End, permanently stored in PVSS "datapoints", and finally mirrored into the PLC datablocks via the OPC mechanism. In addition to this, the Back-End is constantly informed, again through OPC, of any changes in the status of the monitored system . The Back-End then displays all the relevant information to the User, both via an alarm screen and via an interactive synoptic system. This paper describes in greater details some of the ideas behind the design and the implementation of this system.
117272397
Non-linear Resonances with Stong Radiation Damping in LEP
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.
119009661
Determination of coupled-lattice properties using turn-by-turn data
A formalism for extracting coupled betatron parameters from multiturn, shock excited, beam position monitor data is described. The most important results are nonperturbative in that they do not rely on the underlying ideal lattice model. Except for damping, which is assumed to be exponential and small enough to be removed empirically, the description is symplectic. As well as simplifying the description, this leads to self-consistency checks that are applied to the data. The most important of these is a {open_quotes}magic ratio{close_quotes} of Fourier coefficients that is required to be a lattice invariant, the same at every beam position monitor. All formulas are applied to both real and simulated data. The real data was acquired June, 1992 at LEP as part of decoupling studies, using the LEP beam orbit measurement system. Simulated data, obtained by numerical tracking (TEAPOT) in the same (except for unknown errors) lattice, agrees well with real data when subjected to identical analysis. For both datasets, deviations between extracted and design parameters and deviations from self-consistency can be accounted for by noise and signal processing limitations. This investigation demonstrates that the LEP beam position system yields reliable local coupling measurements. It can be conservatively assumed that systems of similar design at the SSC and LHC will provide the measurements needed for local decoupling.