https://doi.org/10.1140/epjc/s10052-008-0689-0
Regular Article - Theoretical Physics
Lowest-lying tetra-quark hadrons in anisotropic lattice QCD
1
International School, Jinan University, Huangpu Road West, 510632, Guangzhou, People’s Republic of China
2
Department of Applied Physics, South China Agricultural University, Wushan Road, 510642, Guangzhou, People’s Republic of China
3
Department of Physics, Jinan University, Huangpu Road West, 510632, Guangzhou, People’s Republic of China
* e-mail: mushe@phys.unsw.edu.au
Received:
22
May
2008
Published online:
22
August
2008
We present a detailed study of the lowest-lying
hadrons in quenched improved anisotropic lattice QCD. Using the π
π and diquark–antidiquark local and smeared operators, we attempt to isolate the signal for I(J
P
)=0(0+),2(0+) and 1(1+) states in two flavour QCD. In the chiral limit of the light-quark mass region, the lowest scalar 4q state is found to have a mass, m
4q
I=0
=927(12) MeV, which is slightly lower than the experimentally observed f
0(980). The results from our variational analysis do not indicate a signature of a tetraquark resonance in I=1 and I=2 channels. After the chiral extrapolation the lowest 1(1+) state is found to have a mass m
4q
I=1
=1358(28) MeV. We analysed the static 4q potential extracted from a tetraquark Wilson loop and illustrated the behaviour of the 4q state as a bound state, unbinding at some critical diquark separation. From our analysis we conclude that the scalar 4q system appears as a two-pion scattering state and that there is no spatially-localised 4q state in the light-quark mass region.
PACS: 11.15.Ha – / 12.38.Gc – / 11.15.Me –
© Springer-Verlag , 2008
