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The small axial charge of N(1535) Reference: Eur. Phys. J. A 37, 263 Collaborator: Dan-Olof Riska. 报告人：安春生 单位：高能物理研究所 中国物理学秋季会议 山东大学， 2008.09.21. Outline. Introduction The five-quark components in N(1535) The axial charge of N(1535) Conclusion. Introduction.
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The small axial charge of N(1535)Reference: Eur. Phys. J. A 37, 263Collaborator: Dan-Olof Riska 报告人：安春生 单位：高能物理研究所 中国物理学秋季会议 山东大学，2008.09.21
Outline • Introduction • The five-quark components in N(1535) • The axial charge of N(1535) • Conclusion
Introduction • Definition of the axial charge The axial charge is defined by with the vanishing transferred momentum
The axial charge of proton (data): Result from NQM (L. Ya. Glozman, Nucl.Phys.A807:38): Result from RQM (D. O. Riska et. al.,PRC70,045204):
New approach: Considering the lowest energy 5q components, we can get:
The axial charge of N(1535) (Toru T. Takahashi, Phys.Rev.D78:011503,2008) Result from NQM: -1/9
The five-quark components in N(1535) • Properties of N(1535) spin: ½ parity: negative • Here we consider the charged one, and for simplicity, we assume that
Hyperfine interaction between quarks Orbital-Flavor-Spin-Color configurations:
The axial charge of N(1535) • In the NQM, the axial charge is given by the matrix element of the non-relativistic single-quark axial-vector charge operator(3-quark case):
Taking the contributions of the 5-quark components into account: • 5-quark components wave function:
Final result Only the first two: The first three term: if we take the assumption • ,and the probabilities fall within the range , then the axial charge is which brackets 0.
conclusion Considering the contributions of the five-quark components: • The axial charge of the nucleon may be decreased. • There is a natural cancellation between the contributions of the three-quark and five-quark components to the axial charge of the N(1535) resonance.
With a proper overall probability of the five-quark components, the axial charge of N(1535) may vanish.
