arXiv:hep-ph/0505040·v1·High Energy Physics — Phenomenology
Non-interacting KN contribution in the QCD sum rule for the pentaquark Theta^+(1540)
Youngshin Kwon (RCNP, Osaka Univ., Japan and Dept. of Phys., Yonsei Univ., Korea)🇯🇵 · Atsushi Hosaka (RCNP, Osaka Univ., Japan)🇯🇵 · Su Houng Lee (Dept. of Phys., Yonsei Univ., Korea)🇰🇷
Abstract
We perform a QCD sum rule analysis for the pentaquark baryon Theta^+ with the non-interacting contribution treated carefully. The coupling of the Theta^+ current to the state is evaluated by applying the soft kaon theorem and vacuum saturation. When using a five-quark current including scalar and pseudo-scalar diquarks, the KN contribution turns out not to be very important and the previous result of the negative parity Theta^+ is reproduced again. The Borel analysis of the correlation function for Theta^+ with the KN continuum states subtracted yields the mass of the J^P= 1/2^- Theta^+ around 1.5 GeV.
Comments: 7 pages, 5 figures, Talk given at Quark Nuclear Physics 2005 at Pyongchang, Korea, February 22-24, 2005