Abstract
We present a detailed study of the lowest-lying \(q^{2}\bar{q}^{2}\) 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 I=04q =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 I=14q =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.
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References
LEPS Collaboration (T. Nakano et al.), Phys. Rev. Lett. 91, 012002 (2003)
DIANA Collaboration (V. Barmin et al.), Phys. Rev. Lett. 91, 252001 (2003)
CLAS Collaboration (V. Kubarovsky et al.), Phys. Rev. Lett. 92, 032001 (2004)
BES Collaboration (J. Bai et al.), Phys. Rev. D 70, 012004 (2004)
BES Collaboration, Phys. Lett. B 598, 149 (2004)
BES Collaboration, Phys. Lett. B 607, 243 (2005)
BES Collaboration (M. Ablikim et al.), Phys. Lett. B 603, 138 (2004)
ZEUS Collaboration, Phys. Lett. B 578, 33 (2004)
Belle Collaboration (S. Choi et al.), Phys. Rev. Lett. 91, 262001 (2003)
CDFII Collaboration (D. Acosta et al.), Phys. Rev. Lett. 93, 072001 (2004)
BARBAR Collaboration (B. Aubert et al.), Phys. Rev. Lett. 93, 041801 (2004)
BARBAR Collaboration (B. Aubert et al.), Phys. Rev. Lett. 90, 242001 (2003)
F. Close, S. Godfrey, Phys. Lett. B 574, 210 (2003)
F. Close, P. Page, Phys. Lett. B 578, 119 (2004)
S. Pakvasa, M. Suzuki, Phys. Lett. B 579, 67 (2004)
C. Wong, Phys. Rev. C 69, 055202 (2004)
E. Braaten, M. Kusunoki, Phys. Rev. D 69, 074005 (2004)
B. Lasscock et al., Phys. Rev. D 72, 014502 (2005) and references therein
F. Oikharu et al., Phys. Rev. D 72, 074503 (2005) and references therein
M. Fukugita et al., Phys. Rev. D 52, 3003 (1995)
M. Alford, R. Jaffe, Nucl. Phys. B 578, 367 (2000)
R. Gupta, A. Patel, S. Sharpe, Phys. Rev. D 48, 388 (1993)
S. Sharpe, R. Gupta, G. Kilcup, Nucl. Phys. B 383, 309 (1992)
H. Suganuma, T. Takahashi, F. Oikharu, H. Ichie, Nucl. Phys. B (Proc. Suppl.) 141, 92 (2005)
C. Alexandrou, G. Koutsou, Phys. Rev. D 71, 014504 (2005)
H. Suganuma, F. Oikharu, T. Takahashi, H. Ichie, Nucl. Phys. A 755, 399 (2005)
H. Suganuma, K. Tsumura, N. Ishii, F. Oikharu, hep-lat/0707.3309v1
R. Jaffe, F. Wilczek, Phys. Rev. Lett. 91, 232003 (2003)
C. Alexandrou, A. Tsapalis, Phys. Rev. D 73, 014507 (2006)
T. Chiu, T. Hsieh, Phys. Rev. D 72, 034505 (2005)
M. Albanese et al., Phys. Lett. B 192, 163 (1987)
C. Morningstar, M. Peardon, Phys. Rev. D 60, 034509 (1999)
M. Okamoto et al. (CP-PACS Collaboration), Phys. Rev. D 65, 094508 (2002)
P. Lacock et al. (UKQCD Collaboration), Phys. Rev. D 51, 6403 (1995)
N. Ishii et al., Phys. Rev. D 71, 034001 (2005)
D. Leinweber, A.W. Thomas, R.D. Young, Phys. Rev. Lett. 92, 242002 (2004)
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Loan, M., Luo, ZH. & Lam, Y.Y. Lowest-lying tetra-quark hadrons in anisotropic lattice QCD. Eur. Phys. J. C 57, 579–587 (2008). https://doi.org/10.1140/epjc/s10052-008-0689-0
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DOI: https://doi.org/10.1140/epjc/s10052-008-0689-0