Isospin symmetry breakings as from QCD sum rules

✍ Scribed by W-Y.Pauchy Hwang

• Book ID: 104336836
• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 276 KB
• Volume: 631
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/s0375-9474(98)00053-0

✦ Synopsis

We investigate isospin symmetry breakings, especially those connected with pion-nucleon couplings and the neutron-proton mass difference, by making use of the method of QCD sum rules in the presence of an external pion field. Manifestations of such isospin symmetry breakings are examined briefly in relation to low-energy nucleon-nucleon 1S0 scatterings. We discuss the prospect of understanding the various isospin symmetry breaking phenomena observed in low-energy nuclear physics by extending chiral perturbation theory (xPT) to include isospin symmetry breakings (ISB). We emphasize that QCD sum rules help to establish xPT/ISB out of QCD by eliminating an excessive number of ISB condensate parameters, making xPT/ISB a worthy extension of xPT. *The author wishes to seknowledse Kwei-Chou Yans, Shi-lln Zhu, and Ernest M. Henley for collaborations and discussions related to the subject presented here.