Quark Sea Effect on Static Properties of Hadron.
Abstract
We study the effect of the quark sea on static properties of hadrons, within the framework of QCD. A QCD Hamiltonian density is used to obtain the quark amplitudes and probability in the lowestorder perturbation theory. The numerical results are obtained by using MIT bag model wavefunctions. A large excitation parameter for sea quark is found. The expectation values for the axial charge g(,A), the proton magnetic moment (mu)(,p), the proton meansquare radius <r(,em)('2)>(,p), and the meansquare radius of the axial charge <r(,ax)('2)> are obtained. Calculations have been done up to the second order of the coupling constant (alpha)(,c) = g('2)/(4(pi)). The results are found to be in rough agreement with experiment for g(,A) and <r(,em)('2)>(,p). The calculated values for (mu)(,p) and <r(,ax)('2)> are found to be smaller than the empirical values by 25%. Employing an approximate Hamiltonian matrix, the wavefunctions and operator matrix elements are then calculated exactly. This modifies the excitation parameters for sea quarks. But the renormalized results for four calculated properties remain roughly the same.
 Publication:

Ph.D. Thesis
 Pub Date:
 1981
 Bibcode:
 1981PhDT.......154B
 Keywords:

 Physics: Nuclear