Poles, the only true resonant-state signals, are extracted from a worldwide collection of partial wave amplitudes using only one, well controlled pole-extraction method

Each and every energy dependent partial-wave analysis is parameterizing the pole positions in a procedure defined by the way how the continuous energy dependence is implemented. These pole positions are, henceforth, inherently model dependent. To reduce this model dependence, we use only one, coupled-channel, unitary, fully analytic method based on the isobar approximation to extract the pole positions from the each available member of the worldwide collection of partial wave amplitudes which are understood as nothing more but a good energy dependent representation of genuine experimental numbers assembled in a form of partial-wave data. In that way, the model dependence related to the different assumptions on the analytic form of the partial-wave amplitudes is avoided, and the true confidence limit for the existence of a particular resonant state, at least in one model, is established. The way how the method works, and first results are demonstrated for the S11 partial wave.Comment: 22 pages, 8 figures, 2 table

A Svarc-Milnor lemma for monoids acting by isometric embeddings

We continue our programme of extending key techniques from geometric group theory to semigroup theory, by studying monoids acting by isometric embeddings on spaces equipped with asymmetric, partially-defined distance functions. The canonical example of such an action is a cancellative monoid acting by translation on its Cayley graph. Our main result is an extension of the Svarc-Milnor Lemma to this setting.Comment: 11 page

Psychoneurotic disturbances among building-site workers living apart from family

Cilj ovog rada bio je ispitati da li postoji povezanost između odvojenosti građevinskih radnika od obitelji, a žive u nastambama poduzeća, i pojave psihičkih smetnji kod tih radnika. Slijedeći dobivene rezultate našlo se da vrsta stanovanja nije povezana s pojavom psihičkih smetnji, no učestalost psihičkih smetnji bila je nešto veća kod mladih i neoženjenih radnika koji žive u nastambama nego u radnika iste dobi koji stanuju u krugu svoje obitelji. Neuroze i psihoze bile su podjednako distribuirane u obje skupine ispitanika bez obzira na vrstu stanovanja.The study aimed at establishing a correlation between building-site workers living apart from their families in a company\u27s lodgings, and the development of psychic disturbances in their behaviour. The results showed that the type of lodgings did not correlate with the development of psychic disturbances. It was found that younger and unmarried workers living in company\u27s accommodation were more prone to exhibiting those symptoms than workers of the same age living with their families. Neurosis and psychosis were equally present in both groups of workers regardless of the type of living quarters. The results seem to be logical as psychic disturbances also tend to develop in stable social environments. This should make one aware of the importance of predisposition for the development of psychic disturbances in any form of community however protective it may be

Strong evidence for nucleon resonances near 1900 MeV

Data on the reaction γp → KþΛ from the CLAS experiments are used to derive the leading multipoles, E0þ, M1−, E1þ, and M1þ, from the production threshold to 2180 MeV in 24 slices of the invariant mass. The four multipoles are determined without any constraints. The multipoles are fitted using a multichannel L þ P model that allows us to search for singularities and to extract the positions of poles on the complex energy plane in an almost model-independent method. The multipoles are also used as additional constraints in an energy-dependent analysis of a large body of pion and photoinduced reactions within the Bonn-Gatchina partial wave analysis. The study confirms the existence of poles due to nucleon resonances with spin parity JP ¼ 1=2−, 1=2þ, and 3=2þ in the region at about 1.9 Ge

Model-independent resonance parameter extraction using the trace of K and T matrices

A model-independent method for the determination of Breit-Wigner resonance parameters is presented. The method is based on eliminating the dependence on the choice of channel basis by analyzing the trace of the K and T matrices in the coupled-channel formalism, rather than individual matrix elements of the multichannel scattering matrix.Comment: 6 pages, 16 figure

Stability of the Zagreb Carnegie-Mellon-Berkeley model

In ref. [1] we have used the Zagreb realization of Carnegie-Melon-Berkeley coupled-channel, unitary model as a tool for extracting pole positions from the world collection of partial wave data, with the aim of eliminating model dependence in pole-search procedures. In order that the method is sensible, we in this paper discuss the stability of the method with respect to the strong variation of different model ingredients. We show that the Zagreb CMB procedure is very stable with strong variation of the model assumptions, and that it can reliably predict the pole positions of the fitted partial wave amplitudes.Comment: 25 pages, 12 figures, 19 table