26 research outputs found

    Nucleon resonances in the fourth resonance region

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    Nucleon and Δ\Delta resonances in the fourth resonance region are studied in a multichannel partial-wave analysis which includes nearly all available data on pion- and photo-induced reactions off protons. In the high-mass range, above 1850\,MeV, several alternative solutions yield a good description of the data. For these solutions, masses, widths, pole residues and photo-couplings are given. In particular, we find evidence for nucleon resonances with spin-parities JP=1/2+...7/2+J^P=1/2^+...7/2^+. For one set of solutions, there are four resonances forming naturally a spin-quartet of resonances with orbital angular momentum L=2 and spin S=3/2 coupling to J=1/2,...,7/2J=1/2,...,7/2. Just below 1.9\,GeV we find a spin doublet of resonances with JP=1/2J^P=1/2^- and 3/23/2^-. Since a spin partner with JP=5/2J^P=5/2^- is missing at this mass, the two resonances form a spin doublet which must have a symmetric orbital-angular-momentum wave function with L=1. For another set of solutions, the four positive-parity resonances are accompanied by mass-degenerate negative-parity partners -- as suggested by the conjecture of chiral symmetry restoration. The possibility of a JP=1/2+,3/2+J^P=1/2^+, 3/2^+ spin doublet at 1900\,MeV belonging to a 20-plet is discussed.Comment: 16 page

    The influence of racial factors on psychiatric diagnosis: A review and suggestions for research

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    Research on race and diagnosis initially focused on black-white differences in depression and schizophrenia. Statistics showing a higher treated prevalence of schizophrenia and a lower prevalence of depression for blacks seemed to support the claim that blacks did not suffer from depression. Others argued, however, that clinicians were misdiagnosing depression in blacks. This article reviews empirical studies of racial differences in individual symptoms and summarizes the evidence on misdiagnosis. It argues that more attention must be paid to resolving two contradictory assumptions made by researchers working in the area of race and diagnostic inference: (1) blacks and whites exhibit symptomatology similarly but diagnosticians mistakenly assume that they are different; (2) blacks and whites display psychopathology in different ways but diagnosticians are unaware of or insensitive to such cultural differences. The article concludes with suggested research directions and a discussion of critical research issues.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44303/1/10597_2004_Article_BF00755677.pd
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