https://doi.org/10.1140/epja/i2011-11099-x
Regular Article - Theoretical Physics
Exploration of hyperfine interaction between constituent quarks via η productions
1
Nuclear theory group, Institute of Modern Physics, Chinese Academy of Sciences, 730000, Lanzhou, China
2
Research Center for Hadron and CSR Physics, Institute of Modern Physics of CAS and Lanzhou University, 730000, Lanzhou, China
3
Graduate University of Chinese Academy of Sciences, 100049, Beijing, China
* e-mail: junhe@impcas.ac.cn
Received:
9
May
2011
Revised:
21
July
2011
Accepted:
5
August
2011
Published online:
25
August
2011
In this work, the different exchange freedom, one gloun, one pion or Goldstone boson, in constituent quark model is investigated, which is responsible to the hyperfine interaction between constituent quarks, via the combined analysis of the η production processes, π − p → ηn and γp → ηp. With the Goldstone-boson exchange, as well as the one-gluon or one-pion exchange, both the spectrum and observables, such as, the differential cross-section and polarized beam asymmetry, are fitted to the suggested values of Particle Data Group and the experimental data. The first two types of exchange freedoms give acceptable description of the spectrum and observables while the one-pion exchange cannot describe the observables and spectrum simultaneously, so it can be excluded. The experimental data for the two processes considered here strongly support the mixing angles for two lowest S 11 sates and D 13 states as about −30° and 6°, respectively.
© SIF, Springer-Verlag Berlin Heidelberg, 2011
