438 research outputs found
Two-particle multiplets splitting as a guideline in nucleon pairing estimations
The ground state multiplet structure for nuclei over the wide range of mass
number was calculated in -approximation and different mass
relations for pairing energy was analysed in this work. Correlation between the
calculated multiplet structure and experimental data offer a guideline in
deciding between mass relations for nucleon pairing.Comment: 6 pages, 2 fig., Proceedings of Intern. Session-Conference of the
Section of Nuclear Physics of PSD RAS (April 12 - 15, 2016, JINR Dubna), to
be published in Journal Physics of Elementary Particles and Atomic Nuclei
(PEPAN
The effects of deformation and pairing correlations on nuclear charge form factor
A set of moderately deformed shell nuclei is employed for testing the
reliability of the nuclear ground state wave functions which are obtained in
the context of a BCS approach and offer a simultaneous consideration of
deformation and pairing correlations effects. In this method, the mean field is
assumed to be an axially symmetric Woods-Saxon potential and the effective
two-body interaction is a monopole pairing force. As quantities of main
interest we have chosen the nuclear form factors, the occupancies of the active
(surface) orbits and the Fermi sea depletion, which provide quite good tests
for microscopic descriptions of nuclei within many body theories. For our
comparisons with results emerging from other similar methods, an axially
deformed harmonic oscillator field is also utilized.Comment: 20 pages, 12 figures, 2 table
Electroexcitation of nucleon resonances at Q^2=0.65 GeV/c^2 from a combined analysis of single- and double-pion electroproduction data
Data on single- and double-charged pion electroproduction off protons are
successfully described in the second and third nucleon resonance regions with
common N* photocouplings. The analysis was carried out using separate isobar
models for both reactions. From the combined analysis of two exclusive
channels, the gamma* p --> N*+ helicity amplitudes are obtained for the
resonances P11(1440), D13(1520), S31(1620), S11(1650), F15(1680), D33(1700),
D13(1700), and P13(1720) at Q2=0.65 GeV/c^2.Comment: 12 pages, 12 figures (eps), Published in PHYSICAL REVIEW C 72, 045201
(2005
Phenomenological analysis of the CLAS data on double charged pion photo and electro- production
First comprehensive data on the evolution of nucleon resonance photocouplings
with photon virtuality Q^2 are presented for excited proton states in the mass
range from 1.4 to 2.0 GeV. N^* photocouplings were determined in
phenomenological analysis of CLAS data on 2 pi photo and electroproduction
within the framework of the JLAB-MSU phenomenological model.Comment: 10 pages, 7 figures (encapsulated postscript
Nucleon Resonance Structure from CLAS and CLAS12 Experiments
The recent results on the photo- and electrocouplings extraction from the reaction of one- and two-pion photo- and electroproduction off protons in the resonances region are presented. The production of two charged pions is of particular importance for evaluation of the photocouplings for the Δ(1620)12 −, Δ(1700)32 −
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