172 research outputs found
Towers of baryons of the quark model band in the large limit
We performed a complete analysis of the spectrum of all the states in the
quark model harmonic oscillator band with in the large
limit including the often disregarded antisymmetric multiplet . We included configuration mixing effects. We found that the states
in the and with fall into nine towers
of degenerate states. We found that nonstrange antisymmetric states fall into
three towers and respond to the same structure as the states in the multiplet. We also showed explicitly the compatibility of these
results and the scattering resonance picture.Comment: 41 pages, 7 tables, v2: minor changes to match published version,
typos in Eqs. (16) and (20) correcte
Target normal single-spin asymmetry in inclusive electron-nucleon scattering in the 1/Nc expansion
The target normal single-spin asymmetry in inclusive electron-nucleon
scattering is studied in the low-energy regime that includes the
resonance. The particular interest in the asymmetry resides in that it is
driven by two-photon exchange effects. It probes the spin-dependent absorptive
part of the two-photon exchange amplitude, which is free of infrared and
collinear singularities and represents the most pristine expression of
two-photon exchange dynamics. The study presented here uses the 1/Nc expansion
of QCD, which combines the and through the emergent SU(4)
spin-flavor symmetry in the baryon sector and allows for a systematic
construction of the transition EM currents. The analysis includes the first
subleading corrections in the 1/Nc expansion and presents results for elastic
and inelastic final states. The asymmetry is found to be in the range
. The resonance plays an important role as an
intermediate state in the elastic asymmetry and as a final state in the
inclusive asymmetry
Aantalsverloop en verspreiding van steltlopers aan de Vlaamse kust, periode 1 juli 1989 tot 30 juni 1990
Many-quark interactions: Large- scaling and contribution to baryon masses
Starting from an effective Hamiltonian modelling a baryon made of
identical quarks in the large- approach of QCD, we obtain analytical
formulas allowing to estimate the contributions of multiquark interactions to
the baryon mass. The cases of vanishing (mass spectrum) and non-vanishing
(baryon melting) temperatures are treated
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