124379270
Strong Interactions and Reactions of Hyperons and Heavy Mesons
Symmetry properties of strong interactions of K mesons and hyperons are reviewed, including: experimental attempts to determine the relative parities of the strange particles; analyses of parity conservation in strong interactions; and studies of various postulated symmetries for K-meson and hyperon interactions. Dynamical aspects of these interactlons are also reviewed, with particular attenti on to the phenomenological treatment of K- low-energy reactions. A bibliography containing 167 references is included. (T.F.H.)
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.
124837005
SEARCH FOR QUARKS WITH THE FERROMAGNETIC LEVITATION ELECTROMETER
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.
85527168
A METHOD TO MEASURE THE BETA-BEATING IN A 90 DEGREES PHASE ADVANCE LATTICE
A method to compute the beta-beating in an accelerator, using as input the measurement of the phase advance of a betatron oscillation between three BPMs (beam position monitors), had been developed in the past[1]. The beauty of this method is that the result does not depend on the the BPM relative errors on the measurement of the oscillation amplitude. Unfortunately this method is not applicable when the phase advance between two of the three BPMs is (close to) 180 degrees. In this latter case the measurement of the amplitude of the beam oscillation should be combined with the phase advance measurement to get a complete picture of the beta-beating. Detecting and filtering BPMs with large gain errors requires some care. A method dealing with these aspects has been developed. Examples obtained by applying the method to real data from LEP and SPS are shown.
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.
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.
17683309
Parasitic energy loss in the LEP superconducting cavities
The energy loss of bunches in the LEP superconducting (SC) cavities has been determined by measuring the closed orbit as a function of current with the beam position monitors located at finite dispersion. This method has already been used in earlier experiments to determine the distribution of the longitudinal impedance of different parts of LEP. In the present experiment the energy loss in two straight sections, containing only SC cavities, was compared with that in sections having both copper cavities and SC cavities. The results confirm the impedance calculations for the two types of cavities. The accuracy of the measurements was considerably improved by determining simultaneously the orbits of bunches with different currents. At the same time with these beam-based impedance measurements, the power dissipation was observed directly by local temperature monitors in different elements: the inter-cavity bellows inside the cryostat, the warm intermodule bellows, and ferrite absorbers which were installed in two places to reduce the energy leaking out of cavities. These observations were correlated with the change of cryogenics power consumption, and showed an unexpected dependence of energy loss on beam energy.
107525573
The Q-Loop : a Function Driven Feedback System for the Betatron Tunes During the LEP Energy Ramp
In normal operation LEP is ramped from injection energy, typically 22 GeV, to energies of over 90 GeV where physics taking takes place. Effective control of the betatron during the ramp is essential to ensure good transmission of stored current. The LEP Q-loop is a feedback system used to control the tunes during the energy ramp. By following a pre-programmed tune function it provides a means of avoiding dangerous resonances and thus beam loss. The basic components the Q-loop will be described, and operational results presented. Emphasis will be given to the problems encountered and the solutions found.