In this thesis, the baryon classification is SU(6) × 0(3) and the strong decay process using generalized Lipkin's rule (G-L) are studied in the basis of the quark model.
At first, the role of SU(3) and SU(6) is briefly reviewed to understand the necessity for the quark and to be able to know the properties of the quark. The baryon and meson are assumed to be the bound state of the quarks, three quarks for baryon and quark-antiquark pair for meson.
It is assumed that the quark has heavy mass and has peculiar statistics such that the symmetric state of spin half particles can be possible and is governed by the nonrelativistic harmonic oscillator force as a first approximation, which enable the states of the quarks to be classified by SU(6) × 0(3).
And the interaction of the hadrons is assumed to be the result of one quark interaction (two quarks is also possible), so called additivity assumption. With such assumption, the higher mass baryon is expected to be the L-excited states of L = 0 quark system which are basic octet (1/$2^+$) and decimet (3/$2^+$).
The classification of baryon is discussed along the line with Horgan and Dalitz, where the mixing is shown to be the result of the L-S coupling of the mass operator, and is compared with SU(3) results.
The Lipkin's rule for the pionic decay is generalized to be applicable to the pseudoscalar mesonic decay; G-L.
It is proved explicitly that the $\ell$ - broken $SU(6)_w$ is equivalent to the G-L in which we can use SU(6) × 0(3) for strong decay process.
The experimental partial width for strong decays of $(56,0^+)_0$ and $(70,1^-)_1$ multiplet are fitted to the G-L with two parameters for $(70, 1^-)_1$ and one for $(56,0^+)_0$ using SU(6) × 0(3) classification in mass fitting.
The result shows that the Δ, N states can be explained well by G-L. But the ∑, ≡, ∧ states give large give large $\chi^2$.
The reason of the disagreement is proved to be the effect of the mixing which is important to the ∑, ≡, ∧ states and which is not unique in the various fitting of the mass.
The detailed fitting according to SU(6) × 0(3) is proposed and the rearrangement picture is suggested to get the concrete picture of the decay process.
이 논문에서는 중입자의 내부 대칭성으로 $SU(6) × O(3)$ 을 도입하고 이 이론에 입각하여 바리온 입자의 분류와 일반화한 Lipkin 의 규칙에 의한 강한 붕괴 작용이 실험 사실을 비교 고찰하여 이론의 타당성을 조사 검토 하였다.
실험치와 비교하여 본 결과 Δ, N 입자들은 잘 설명할 수 있는 반면 ∑, ≡, ∧ 입자들은 잘 설명되지 않는 것을 보았다. 이러한 결과는 ∑, ≡, ∧ 입자들의 $SU(6) × O(3)$ 에 의한 기약표현 (irreducible representation)에 대한 정밀한 연구가 필요 하다는 것을 밝혀주고 있다.
강한 붕괴 작용의 구체적인 모형으로 Quark 입자의 재배열 (rearrangement) 모형에 대한 가능성도 고찰하였다.
