142 research outputs found
Possible eta-mesic 3He states within the finite rank approximation
We extend the method of time delay proposed by Eisenbud and Wigner, to search
for unstable states formed by eta mesons and the 3He nucleus. Using few body
equations to describe eta-3He elastic scattering, we predict resonances and
unstable bound states within different models of the eta-N interaction. The
eta-3He states predicted within this novel approach are in agreement with the
recent claim of the evidence of eta-mesic 3He made by the TAPS collaboration.Comment: 10 pages LaTex, 3 figure
The structure effects in polarization and cross section in inelastic A(p,p')X reaction with the 40Ca and 12C nuclei at 1 GeV
The polarization of the secondary protons in inelastic (p,p') reaction on the
40Ca and 12C nuclei at the initial proton energy 1 GeV was measured in the wide
range of the scattered proton momenta at a laboratory angle 21 degree. The
cross section of the reactions were measured as well. The outgoing protons from
the reaction were detected using a magnetic spectrometer equipped with a
multiwire-proportional chambers polarimeter. A structure in the polarization
and cross section data, related probably to scattering of the nucleon
correlation in the nuclei, was observed.Comment: 13 pages, 5 figures, 7 table
Does the Sigma(1580)3/2- resonance exist?
Precise new data for the reaction are presented in
the c.m. energy range 1565 to 1600 MeV. Our analysis of these data sheds new
light on claims for the resonance, which (if it exists
with the specified quantum numbers) must be an exotic baryon because of its
very low mass. Our results show no evidence for this state.Comment: 4 pages, 4 figure
Search for the Cryptoexotic Member of the Baryon Antidecuplet 1/2+ in the Reactions pi- p --> pi- p and pi- p --> K L
The main goal of this proposal is the search for a narrow cryptoexotic
nucleon resonance by scanning of the pi- p system invariant mass in the region
(1610-1770) MeV with the detection of pi- p and K Lambda decays. The scan is
supposed to be done by the variation of the incident pi- momentum and its
measurement with the accuracy of up to +-0.1% (better than 1 MeV in terms of
the invariant mass in the whole energy range) with a set of proportional
chambers located in the first focus of the magnetooptical channel. High
sensitivity of the method to the resonance under search is shown. The secondary
particles scattered from a liquid hydrogen target are detected by sets of the
wire drift chambers equipped with modern electronics. The time scale of the
project is about 3 years. The budget estimate including manpower, the apparatus
and operation cost, is about 40 million rubles. The beam time required is (4-6)
two week runs on "high" (10 GeV/c) flattop of the ITEP proton synchrotron.Comment: 16 pages, 10 figures. v2: an acknowledge adde
Measurement of Inverse Pion Photoproduction at Energies Spanning the N(1440) Resonance
Differential cross sections for the process pi^- p -> gamma n have been
measured at Brookhaven National Laboratory's Alternating Gradient Synchrotron
with the Crystal Ball multiphoton spectrometer. Measurements were made at 18
pion momenta from 238 to 748 MeV/c, corresponding to E_gamma for the inverse
reaction from 285 to 769 MeV. The data have been used to evaluate the gamma n
multipoles in the vicinity of the N(1440) resonance. We compare our data and
multipoles to previous determinations. A new three-parameter SAID fit yields 36
+/- 7 (GeV)^-1/2 X 10^-3 for the A^n_1/2 amplitude of the P_11.Comment: 14 pages, 8 figures, submitted to PR
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