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.
119236559
Some remarks on a paper by G.-S. Yang and H.-C.Kim: Mass splitting of SU(3) baryons within a chiral soliton model
In a recent paper Yang and Kim discuss the lowest baryon mass formulas using a chiral soliton model. However, contrary to their assertion, their result is not equivalent to a generalized Gell Mann-Okubo mass formula derived (G.Morpurgo,1992) using only general properties of QCD (The General Parameterization method). The reason for the non equivalence is that the generalized mass formula includes all the main terms that break flavor at second order, whereas the Authors above do not go beyond first order flavor breaking (and should therefore find the usual Gell Mann Okubo formula). This is not so, due to some inconsistencies. Below we confine to the part of the Yang-Kim paper dealing with the mass formula. We will not consider the other items of their paper. 1.Second order versus first order in flavor breaking. As stated in the Abstract, I will consider only the part of the paper of Yang and Kim [1] dealing with the Gell Mann-Okubo mass formula (see the generalized Gell Mann-Okubo mass formula Eqs.(1) below) derived [2] many years ago. In the Eqs.(1,2) below the particle symbols stay for the particle masses. 1 2 (p+ Ξ) + T = 1 4 (3Λ + 2Σ − Σ) (1) where T stays for T ≡ Ξ∗− − 1 2 (Ω + Σ∗−) (2) The fit to the data depends on whether we use the conventional or the pole values for the masses of the resonances appearing in T : l.h.s. = 1132.36± 0.7MeV, r.h.s. = 1133.93± 0.04MeV (conventional) l.h.s. = 1133.86± 1.25MeV, r.h.s. = 1133.93± 0.04MeV (pole) (3) In Eq.(1) the value of T is 5.7±0.7MeV . The Eq.(1), written with the signs of the charges indicated in it, includes correctly the effects of the e.m. contributions to the masses. (See in Ref.[2], the text and the footnote 9). Note from Eq.(3) e-mail morpurgo@ge.infn.it
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.
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.
122238217
A relation between the charge radii of π+,K+,K0 derived by the general QCD parametrization
We derive, using the general QCD parametrization, the approximate relation r2(π+) − r2(K+) − r2(K0) where the r's are the charge radii. The relation is satisfied but the experimental errors are still sizeable. The derivation is similar to (but even simpler than) that for r2(p) − r2(n) r2(Δ+) (Phys. Lett. B, 448 (1999) 107).
124837005
SEARCH FOR QUARKS WITH THE FERROMAGNETIC LEVITATION ELECTROMETER
120297805
SASD and the CERN / SPS run-time coordinator
Abstract Structured Analysis and Structure Design (SASD) provides us with a handy way of specifying the flow of data between the different modules (functional units) of a system. But the formalism loses its immediacy when the control flow has to be taken into account as well. Moreover, due to the lack of appropriate software infrastructure, very often the actual implementation of the system does not reflect the module decoupling and independence so much emphasized at the design stage. In this paper the run-time coordinator, a complete software infrastructure to support a real decoupling of the functional units, is described. Special attention is given to the complementarity of our approach and the SASD methodology.
107933425
First trial of BOM harmonic analysis
18819445
Measurements and Visualization of the Transverse Phase-Space Topology at LEP
The LEP Beam Orbit Measurement system (BOM) allows for the acquisition of the beam position at each Beam Position Monitor (BPM) for over 1000 consecutive turns. By synchronizing the acquisition with a kick given to the beam, we can investigate the behavior of the beam under different conditions. In particular, starting from the data of one BPM, we can apply a simple mathematical manipulation to build a ”virtual” BPM, with a phase advance of 90 degrees. Plotting the real BPM against the virtual one, we can observe the evolution of the beam in the phase-space. An appropriate coloring technique is used, to help the User finding his way through the data. Fixed points in the phasespace can be put in evidence, as well as the beam behavior in their neighbourhood. Quantities like the tune, the beam detuning as function of the position amplitude and the beam damping can be studied in this way. Significant examples from real life will be shown.
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.
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.