Quark models of dibaryon resonances in nucleon-nucleon scattering
- Department of Physics, Nanjing Normal University, Nanjing 210097 (China)
- Department of Physics, Southeast University, Nanjing 210094 (China)
- Department of Physics, Nanjing University, Nanjing 210093 (China)
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095 (United States)
We look for {delta}{delta} and N{delta} resonances by calculating NN scattering phase shifts of two interacting baryon clusters of quarks with explicit coupling to these dibaryon channels. Two phenomenological nonrelativistic chiral quark models giving similar low-energy NN properties are found to give significantly different dibaryon resonance structures. In the chiral quark model (ChQM), the dibaryon system does not resonate in the NNS waves, in agreement with the experimental SP07 NN partial-wave scattering amplitudes. In the quark delocalization and color screening model (QDCSM), the S-wave NN resonances disappear when the nucleon size b falls below 0.53 fm. Both quark models give an IJ{sup P}=03{sup +}{delta}{delta} resonance. At b=0.52 fm, the value favored by the baryon spectrum, the resonance mass is 2390 (2420) MeV for the ChQM with quadratic (linear) confinement, and 2360 MeV for the QDCSM. Accessible from the {sup 3}D{sub 3}{sup NN} channel, this resonance is a promising candidate for the known isoscalar ABC structure seen more clearly in the pn{yields}d{pi}{pi} production cross section at 2410 MeV in the recent preliminary data reported by the CELSIUS-WASA Collaboration. In the isovector dibaryon sector, our quark models give a bound or almost bound {sup 5}S{sub 2}{sup {delta}}{sup {delta}} state that can give rise to a {sup 1}D{sub 2}{sup NN} resonance. None of the quark models used have bound N{delta}P states that might generate odd-parity resonances.
- OSTI ID:
- 21199542
- Journal Information:
- Physical Review. C, Nuclear Physics, Vol. 79, Issue 2; Other Information: DOI: 10.1103/PhysRevC.79.024001; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
- Country of Publication:
- United States
- Language:
- English
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