We propose a new interpolating field for S11 (1535) to determine its mass from QCD sum rules. In the nonrelativistic limit, this interpolating field dominantly reduces to two quarks in the s-wave state and one quark in the p-wave state. An optimization procedure, which makes use of a duality relation, yields the interpolating field which overlaps strongly with the negative-parity baryon and at the same time does not couple at all to the low-lying positive-parity baryon. Using this interpolating field and applying the conventional QCD sum rule analysis, we find that the mass of S11 is reasonably close to the experimentally known value, even though the precise determination depends on the poorly known quark-gluon condensate. Hence our interpolating field can be used to investigate the spectral properties of S11 (1535).
Bibliographical noteFunding Information:
SHL was supported in part by the by the Basic Science Research Institute program of the Korean Ministry of Education through grant no. BSRI-95-2425, by KOSEF through the CTP at Seoul National University and by Yonsei University Research Grant. SHL also thanks DAAD and KOSEF for financial support while visiting GSI. HK was supported by KOSEF.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics