On Baryon Isomultiplet Mass Splittings

• Main Authors: Bi-Ching Shih, 施筆青
• Other Authors: Shih-Nan Yang
• Format: Others
• Language: en_US
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/98988029273849805612

碩士 === 國立臺灣大學 === 物理學研究所 === 89 === Baryon isomultiplet mass differences have been discussed for many years. The effect of the mass difference \delta m=m_d-m_u on the isomultiplet mass shifts was studied by Isgur within the constituent quark model. The u-d quark mass difference was determined to be 6 MeV in Isgur's analysis of the baryon isomultiplet mass splittings. In this work, we extend Isgur's previous analysis within a chiral quark model where pion-quark coupling is assumed. The pion-quark coupling generates a one-pion-exchange (OPE) quark-quark interaction which in charge-dependent if mass difference between charged and neutral pion is taken into account. With the inclusion of the charge-dependent OPE quark-quark interaction, we find that a best fit to the existing isomultiplet mass splittings gives a value of \delta m=6.3 MeV.