A new approach to nonleptonic weak interactions is presented. It is argued that the presence and violation of the / AT / = rule as well as those of the quark-line selection rules can be explained in a unified way, along with other fundamental physical quantities [such as the value of g,(O) and the smallness of the isoscalar nucleon magnetic moments], in terms of a single dynamical asymptotic ansatz imposed at the level of observable hadrons. The ansatz prescribes a way in which asymptotic flavor S U ( N ) symmetry is secured levelwise for a certain class of chiral algebras in the standard QCD model. It yields severe asymptotic constraints upon the two-particle hadronic matrix elements of nonleptonic weak Hamiltonians as well as QCD currents and their charges. It produces for weak matrix elements the asymptotic A? = rule and its charm counterpart for the ground-state hadrons, while for strong matrix elements quark-line-like approximate selection rules. However, for the less important weak two-particle vertices involving higher excited states, the / A? / = rule and its charm counterpart are in general violated, providing us with an explicit source of the violation of these selection rules in physical processes.

We calculate the strong AAT coupling constant g2/4r and the weak axial-vector coupling constant [gA (0)lAA without using SU(6) symmetry. The method is based on the dynamical ansatz of level realization of asymptotic flavor SU(2) symmetry, applied to the charge-charge and chargecurrent SU(2) 8 SU(2) chiral algebras. We predict that g 2 / h = 125 and [gA(0)]A++A+ = 1.30.Recently an elaborate isobar-model partial-wave analysis of a p -+ a + .~-n bubble-chamber events yielded'e2 a value of the strong AAa coupling constant (g2/4a) 2 4 0 + 20, a value which is considerably smaller than the several previous theoretical estimates based on SU(6),3 ~~( 1 2 1 ,~ the quark model,'superconvergence relation^,^,^ the MIT bag model with the Goldberger-Treiman relation as discussed in Ref. 1, and ~t h e r s .~ In view of this, we wish to present in this paper a new evaluation of the coupling constant by extending the result of previous work9 (referred to as I throughout this paper), which has been successfully applied to closely related problems. The work, without introducing the concept of SU(6) symmetry, has produced correct values for the weak axial-vector coupling constants [gA (0) I, , and [gA (0) I A, and a good nucleon-anomalous-magnetic-moment relation kp = -kn, etc. As a by-product we also calculate the weak axial-vector coupling constant [gA (0) I AA.In the realization of a certain class of chiral-SUL(2) C 3 SUR (2)-type charge-charge and chargecurrent equal-time commutators by observable hadrons, our technique utilizes the dynamical ansatz that flavor SU(N) symmetry should be secured levelwise in the asymptotic infinite-momentum limit. In this approach, the quark chiral algebras [A,, a = a + , 3, a-, is the SU(2) axial charge] such as One can then derive (nonperturbative) constraintswithout assuming SU(6) symmetry-among the asymptotic hadronic matrix elements of the vector VL (x) and axial-vector A! (x) currents (p=O, 1,2,3), with 1 -03 and T+w, as well as among those of the axial-vector charges, i.e., with 1 -w . A denotes the helicity and a, P , and y the physical SU(2) indices ( a + , 3,a-1.As in I, we define the relevant asymptotic axialvector ground-state baryon (A = +) matrix elements as (suppressing t -CO)In addition, we also consider, in this paper, the helicity-+ asymptotic axial-vector matrix elementIn I, we have derived, along with other relations, the following constraints among the above asymptotic matrix elements f, g, and h, namely, are regarded simply as indispensable constraints imHere, among the sum over the whole set of singleposed by (confined) quarks and gluons on the world particle hadron intermediate states inserted between of observable hadrons with which we solely deal. In the two axial charges of one of the algebras of Eq. response to the requirements of SU(3) color sym-(I), i.e., [A.+,A,-1 = 2 V3, we have denoted the fracmetry, hadrons are assumed to obey the level scheme tional contribution from the groundstate baryons of (mainly qijand qqq) the constituent quark model. 1 + (which consist of...