Phenomenological Study of Baryons in Jp= 1/2+ State

Abstract

With the upcoming accelerator and detectors, lot of information about the hadrons and their properties are coming. In addition to hadron, lots of unknown particles are also seen with different properties and specific quantum number. In the present thesis, our approach is to study through phenomenological models, such properties of the hadrons. The thesis describes the properties of hadrons (for maximum of cases) especially of baryons octet in Jp= 1/2+ state. With the number of theoretical approaches available, we made the approach to study these baryon in non-relativistic model such as SU(6) simple quark model with the valence quarks and combination of the sea quarks. Here we assume the quarks and gluon of the specific baryon to behave as static candidates with their quantum number giving total wave function to the baryon. Our motivation to choose the present model is to justify the results at the experiments to check the validity of the available theoretical approaches and models developed so far in literature. For this purpose we use the effective mass and effective charge of the quarks combing to form the hadron. The effective mass and screening charge have been studied, using constituent quark model in past to show, how baryon magnetic moments varies in the presence of these effects. We studied the baryon octet with such combined effects of effective mass and screened charges in addition to the modification in the hyperfine splitting value which is taken to be 200 MeV. Besides that we made an attempt to study the baryon wave function in the presence of the orbiting valence quarks, allowing the study of the non-relativistic model with the spin structure and give the expression for the spin in term of the coefficients of the baryon wave function. We further use it to calculate the magnetic moment of baryon in the presence of spin and orbital motion of quarks i.e. valence quarks and calculated the best fit value of the parameters.