手征夸克模型下ud(ss)四夸克态研究.pdf

1 31 ò 1 9 Ï p U Ô n † Ø Ô n Vol. 31, No. 9
2007 c 9  HIGH ENERGY PHYSICS AND NUCLEAR PHYSICS Sep., 2007
Chiral Quark Model Study of ud¯s¯sTetraquark States *
ZHANG Zong-Ye1 WANG Wen-Ling2;1) HUANG Fei3 YU You-Wen1 LIU Feng2
1 (Institute of High Energy Physics, CAS, Beijing 100049, China )
2 (Institute of Particle Physics, Huazhong Normal University, Wuhan 430079, China)
3 (CCAST (World Laboratory), Beijing 100080, China)
Abstract The energies of the low-lying isoscalar and isovector ud¯s¯sconfigurations with spin-parity J P = 0+,
1+, and 2+ are calculated in the chiral SU(3) quark model and the extended chiral SU(3) quark model by using
the variational method. The model parameters are determined by the same method as in our previous work,
and they still can satisfactorily describes the nucleon-nucleon scattering phase shifts and the hyperon-nucleon
cross sections. The s-channel annihilation interaction is fixed by the masses of K and K∗ mesons, and the
configuration mixing is considered. The results show that the ud¯s¯sconfiguration with I = 0 and J P = 1+ lies
∗∗∗
lower than the K K threshold, and furthermore, this state has a very small ponent, thus it can be
treated as a possible tetraquark candidate.
Key words tetraquark state, quark model, chiral symmetry
1 Introduction In the past few years, the chiral SU(3) quark
model and the extended ch