Properties of Baryons in the Chiral Quark Model Tommy Ohlsson Teknologie licentiatavhandling Kungliga Tekniska Hogskolan¨ Stockholm 1997 Properties of Baryons in the Chiral Quark Model Tommy Ohlsson Licentiate Dissertation Theoretical Physics Department of Physics Royal Institute of Technology Stockholm, Sweden 1997 Typeset in LATEX Akademisk avhandling f¨or teknologie licentiatexamen (TeknL) inom ¨amnesomr˚adet teoretisk fysik. Scientific thesis for the degree of Licentiate of Engineering (Lic Eng) in the subject area of Theoretical Physics. TRITA-FYS-8026 ISSN 0280-316X ISRN KTH/FYS/TEO/R--97/9--SE ISBN 91-7170-211-3 c Tommy Ohlsson 1997 Printed in Sweden by KTH H¨ogskoletryckeriet, Stockholm 1997 Properties of Baryons in the Chiral Quark Model Tommy Ohlsson Teoretisk fysik, Institutionen f¨or fysik, Kungliga Tekniska H¨ogskolan SE-100 44 Stockholm SWEDEN E-mail:
[email protected] Abstract In this thesis, several properties of baryons are studied using the chiral quark model. The chiral quark model is a theory which can be used to describe low energy phenomena of baryons. In Paper 1, the chiral quark model is studied using wave functions with configuration mixing. This study is motivated by the fact that the chiral quark model cannot otherwise break the Coleman–Glashow sum-rule for the magnetic moments of the octet baryons, which is experimentally broken by about ten standard deviations. Configuration mixing with quark-diquark components is also able to reproduce the octet baryon magnetic moments very accurately. In Paper 2, the chiral quark model is used to calculate the decuplet baryon ++ magnetic moments. The values for the magnetic moments of the ∆ and Ω− are in good agreement with the experimental results.