Takao Kaneko

Analytic Solution for Resonant Mixing of Solar Neutrinos

Resonant mixing of neutrinos, pointed out by Mikheyev and Smirnov,l) may give a solution of solar neutrino puzzle. Several authors have studied this problem using numerical methods.) However, analytic solution for the time development of neutrino mixing in matter is not yet obtained. Here we wish to derive an exact solution for a simplified solar model. We assume an exponential density distribution in the Sun; p( r) ~ exp( ar), where r is distance from the center of the Sun and a is some constant. This approximation is rather good except for the core region of the Sun. Then the time development of flavour eigenstate ))e, produced at the core of the Sun, is described as

The Kl3-Decay and Scalar Coupling in the Weak Interactions of Urbaryons

In a previous letter,t> we discussed the magnitude of the pseudo-scalar coupling in the weak interaction of urbaryons (quarks). There, upper limits on the strength of the pseudo-scalar coupling were obtained depending on the bare mass of the urbaryons. Here in this note we want to discuss the magnitude of the scalar coupling which might exist in the weak interactions of urbaryons using the recent experimental data on the parameter e in K 18 decays. We assume the weak interaction Hamiltonian responsible for K18 decay as G Hw= .y2 {as(Polo) (l (1+r5)11)

A Possible Scheme for the Nonleptonic Decays of Hyperons

Nonleptonic decays of hyperons are discussed in the unitary symmetrical [x o] composite model for baryons, where x and (} are triplet spinor and scalar (or pseudo-scalar) fields respectively. The decays are assumed to occur through two different mechanisms jj~o+n, x~x and jj~jj, x~x+n. Several relations among the decay amplitudes, including the wellknown Sugawara-Lee relation for the parity violating part and a new sum rule 2P(S_ -)