Pion Induced Double Charge Exchange Reaction at Pure Nucleonic Level

The two pure nucleonic mechanisms (the conventional sequential mechanism and the two-nucleon pion absorption-emission mechanisml^[1]) are studied within a unified framework of Distorted Wave Impulse Approximation (DWIA). The distorted pion waves are obtained by solving the Klein-Gordon equation with the first-order optical potential. The difference between this approach and the eikonal approximation is showed. For the two-nucleon pion absorption-emission mechanism the effective Landau-Migadal interaction of Pines, et al.^[2] is used for the two bound nucleons, the result is compared with that by using the Paris force. By combining theee two mechanism the O⁰ excitation functions for the DCX reactions to the isobaric analog states on the ¹⁴C, ¹⁸O, ²⁶Mg and ⁴²Ca are calculated and compared with the experimental data.     

IONIZATION OF THE HYDROGEN NEGATIVE ION IN A UNIFORM ELECTRIC FIELD

The ionized Lifetime of the hydrogen negativeion in a uniform electric field is again calculated by using improved perturbation theory.The choice of the H^--ion wave function and the normalization of wave function of continuous state are discussed. The numerical calculations by using Rotenberg-Stein wave function with five parameters are performed. Comparison of our results with experimental results obtained by G. M. Stinson et al. is given.     

IS THE NEUTRINO MASS EQUAL TO 34 eV?--A DISCUSSION OF THE ATOMIC EFFECT IN THE β-DECAY OF H3

In evaluating the β-spectrum of atomic H³ a more accurate formula is obtained. in which the first three transitions leading to the Lowest three states of ³He⁺ are treated exactly, and the cJosure approximation is used to estimate the contribution from all excited states with n>3.The formula obtained is compared with what is used by Lyubimov et al.^[1] in determining the neutri-no mass. As a result it has been shown that the formula used by Lyubimov et al. does not yield an adequate accuracy. Especially the end-point energy they obtained may differ from the true value by 13.6 ev, which would cause an uncertainty of the same order inthe value of the neutrino mass.     

THE PERTURBATION EXPANSION OF THE QUANTIZED COMPOSITE FIELD THEORY AND GAUGE INVARIANCE

In this paper we introduce the concept of "same order" in the perturbution expansion of the quatized composite field theory which is different from single particle theory. For example, in the case of Q. E. D., "same order" is defined by means of a coupling constant, but here it closely relates the operators occuring in the B. S. equations. Feymann graphs of the "same order" are defined for different kinds of transitions in the composite field theory. Finally, we prove that guage invariance is a natural result as long as all "same order" Feymann graphs are calculated for an electromagnetic transition between composite particles.     

COMPOSITE FIELD THEORY AND THE STRATON MODEL(Ⅱ)

On the basis of previous papers,this work discusses the theory of composite fields composed of colored stratons.Varicus equivalent representations of the S-matrix elements are given.The formulae for the transition matrix elements between states involving baryons in the theory of Straton Model are derived.Finally,the field- current relations are extended to spin 1/2 baryons and their applications are discussed.     

THE MIXEFIFNECTG OF Z0 AND TOPONIUN

It is shown that the mixing effect between the Z⁰ and the toponium will significantly affect various properties of toponium state.     

AN ALTERNATIVE APPROACH IN NUCLEAR DOUBLE BETA DECAY THEORY

A new formula as a series of commutators of two axial vector currents and the nuclear Hamiltonian H_S derived for estimating the 2β-decay nuclear matrix element without using explicitly the closure approximation. With a simple assumption of the nuclear wave function and the Hamiltonian H_S, it is shown that the leading term in 2υ-2β decay matrix element vanishes and thus the smallness of 2υ-2β decay probability seems to be understood.     

C12(d,p)C13和Ca40(d,p)Ca41基态反应质子的角分布

本实验测量了C¹²(d,p)C¹³及Ca⁴⁰(d,p)Ca⁴¹基态反应质子群的角分布和微分截面。氘核能量为13.3MeV,对C¹²和Ca⁴⁰的反应,其测量角度范围分别为3°—167°和10°—164°,每隔2.5°或5°测量一点,其主要结果如下:(1)对于这两群质子,在主削裂峯附近的实验点和用简单Butler理论算得的理论角分布曲线都符合得相当好;理论计算数据对实验数据在主峯处归一;由此而定得的核能级参数与前人所得到的是一致的。(2)大角度区的实验截面数值没有减小到象Butler理论所要求的那样小,并有非常明显的次极大出现,其位置与Butler理论所预言的不一致;这些特点可以用扭曲波理论来解释,非氘核削裂机制也可能有部分贡献。(3)在C¹²(d,p)C¹³反应中,前角度区的截面有很大下降,而后角区则有明显的增加,这些现象都和Butler理论不一致;然而,这也可以用扭曲波来解释。(4)用主峯处的截面和Butler理论算得的基态的约化宽度,对C¹²(d,p)C¹³和Ca⁴⁰(d,p)Ca⁴¹反应分别为r²=0.17和0.041;用扭曲波理论计算时,则得到较大的r²值,后者更接近于单粒子模型所预言的数值,基于上面这些事实,对本实验的数据使用扭曲波理论来进行分析似乎是值得的。     

Competitive Sorption of Copper and Nickel Ions from Aqueous Solution Using Peat

Bicomponent aqueous solutions of copper and nickel ions have been used to investigate the sorption of metal ions onto peat. Peat, a low cost sorbent, has shown a high capacity for the sorption of single component metal ions attributed to extensive carboxylic acids within its structure. Copper and nickel ions were selected as typical metals in the effluents of electroplating industries. The effects of competitive sorption in batch systems were studied at various metal ion concentrations. In this study the Butler and Ockrent model was modified using a coefficient, . Two models were developed based on the interaction coefficient . The first model incorporates a constant fixed factor for each metal ion into the Butler-Ockrent equation. The second model incorporates a variable factor into the Butler-Ockrent equation; this interaction factor varies as a function of sorbent surface coverage. Predicted equilibrium data are found to be in excellent agreement with experimental values using both modified models for various mole ratios of copper and nickel ions in competitive sorption.