Prog. Theor. Phys. Supplement No.168 (2007) pp. 54-57
Pentaquarks in QCD Sum Rules
1Department of Physics, Tokyo Institute of Technology, Tokyo 152-8550, Japan
2Kokugakuin University, Tokyo 150-8440, Japan
3Institute of Particle and Nuclear Studies,
High Energy Accelerator Research Organization,
Tsukuba 305-0801, Japan
4Yukawa Institute for Theoretical Physics, Kyoto University,
Kyoto 606-8502, Japan
QCD sum rules for pentaquarks are studied.
We point out that naive pentaquark correlations function include
two-hadron-reducible contributions, which are given by convolution
of baryon and meson correlation functions and have nothing to do
with the pentaquark.
We show that the two-hadron-reducible contributions are large in the
operator product expansion of the correlation functions.
Instead, we propose to use the two-hadron-irreducible correlation
function, which is obtained by subtracting the two-hadron-reducible
contribution from the naive correlation function.
How large the two-hadron-reducible contributions are in the OPE is
demonstrated through the application to spin-1/2 and 3/2 states
of the pentaquark.
DOI : 10.1143/PTPS.168.54
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